feat: add versioning and changelog system

Conventional-Commit-driven version bumps (scripts/bump.py), a commit-msg validation hook, and a /release-notes workflow that produces a human-reviewed CHANGELOG.md. Adds an in-app version badge + 'What's new' dialog on the launcher. The version is single-sourced from pyproject.toml (cim_suite.__version__), and the deterministic bump backbone lives in scripts/release/ with tests in tests/release/. Marks the 1.0.0 baseline.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.claude/commands/release-notes.md

@@ -0,0 +1,44 @@
+---
+description: Draft plain-language CHANGELOG.md release notes from commits since the last version, for human review before committing.
+---
+
+You are drafting the human-facing release notes for the CIMTechniques Service Suite.
+The git history is the technical record; `CHANGELOG.md` is what non-technical users
+read. Accuracy is paramount — **never invent a user-facing benefit a commit doesn't
+support**, and when a commit's user impact is unclear, flag it for the user instead of
+guessing.
+
+Follow these steps exactly:
+
+1. **Collect the commits.** Run:
+   ```
+   .venv\Scripts\python scripts/release_notes.py --json
+   ```
+   If there is no version tag yet and the digest reaches back into pre-rewrite history,
+   ask the user for a `--baseline <commit-or-tag>` and re-run with it. The JSON gives you
+   `current_version`, `suggested_version`, `suggested_bump`, and commits bucketed into
+   `features`, `fixes`, `breaking`, and an `internal_count`.
+
+2. **Draft entries** in Keep a Changelog format for the **suggested_version** (or a
+   version the user specifies), dated today:
+   - Group under **Added / Changed / Fixed / Removed** — omit any empty group.
+   - `feat` commits → usually Added (or Changed if they alter existing behavior).
+     `fix` → Fixed. `breaking` → call out clearly (often Changed/Removed).
+   - Write for a non-technical reader: explain **what** changed and **why it matters to
+     them**, not the implementation. One bullet per user-visible change; merge related
+     commits into a single clear bullet.
+   - Collapse all internal work (refactor/test/chore/style/docs/build/ci) into at most a
+     single line: "Maintenance and under-the-hood improvements." Drop it if there were
+     none.
+   - Flag any commit whose user impact you're unsure of, and ask rather than guess.
+
+3. **Show the draft to the user** in chat and ask them to edit/approve. Do **not** write
+   the file yet.
+
+4. **Only after approval**, prepend the approved entry above the previous version's entry
+   in `CHANGELOG.md` (reverse-chronological). Do not auto-commit; leave the change in the
+   working tree for the user unless they ask you to commit it.
+
+5. If the version number should change, remind the user to run
+   `.venv\Scripts\python scripts/bump.py` (which is deterministic and edits
+   `pyproject.toml`). You never set the version number yourself.

.gitattributes

@@ -1,5 +1,7 @@
 # Normalize line endings; keep legacy VB6 sources as-is.
 * text=auto eol=lf
+# The commit-msg hook is run by git's sh; CRLF would break the shebang. Pin LF.
+/.githooks/** text eol=lf
 *.frm text eol=crlf
 *.bas text eol=crlf
 *.vbp text eol=crlf

.githooks/commit-msg

@@ -0,0 +1,16 @@
+#!/bin/sh
+# Validate the commit message against the Conventional Commit format.
+# Delegates to scripts/commit_msg_hook.py (logic is unit-tested in tests/release).
+# Installed via: python scripts/setup_hooks.py  (sets core.hooksPath -> .githooks)
+
+hook_dir=$(dirname "$0")
+script="$hook_dir/../scripts/commit_msg_hook.py"
+
+for py in python python3 py; do
+    if command -v "$py" >/dev/null 2>&1; then
+        exec "$py" "$script" "$1"
+    fi
+done
+
+echo "commit-msg hook: no python interpreter found on PATH; skipping validation" >&2
+exit 0

CHANGELOG.md

@@ -0,0 +1,28 @@
+# Changelog
+
+All notable changes to the CIMTechniques Service Suite are recorded here in plain
+language, for the people who use it. (The full technical record lives in the project's
+git history.)
+
+This project follows [Keep a Changelog](https://keepachangelog.com/) and
+[Semantic Versioning](https://semver.org/): the version number is `MAJOR.MINOR.PATCH`.
+
+## 1.0.0 - 2026-06-06
+
+First release of the unified **CIMTechniques Service Suite** — one application that
+brings the separate legacy service tools together under a single, modern interface.
+
+### Added
+- **One app for every instrument.** A start page where you pick your service cable /
+  COM port once, then open the tool you need.
+- **DA-12 Monitoring Station Service Tool** — configure and monitor DA-12 sensor
+  stations: sensors, alarm limits, statistics, and calibration.
+- **DA-07 (eLink) Service Tool** — set up and monitor DA-07 stations, their pods,
+  and channels.
+- **IOModbus Service Utility** — read and write supported Modbus devices using a
+  built-in device catalog.
+- **Setting history.** The suite remembers configuration changes made to your DA-12
+  and DA-07 stations, so you can see what changed and when.
+- **Export to spreadsheet.** Any data screen can be saved to an Excel (`.xlsx`) file.
+- **What's new.** The current version and these release notes are shown right on the
+  start page.

CLAUDE.md

@@ -213,4 +213,17 @@ test fixtures.
   checklist.
 - **Spreadsheet export:** every data screen can be exported to `.xlsx`; the engine is
   `cim_suite/core/export/` and the per-module adoption checklist is in `docs/EXPORT.md`.
+- **Versioning & changelog:** SemVer, single-sourced from `[project] version` in
+  `pyproject.toml` (`cim_suite.__version__` reads it; the frozen build bundles the file).
+  Commits are Conventional Commits (`<type>: <desc>`) — validated by `.githooks/commit-msg`
+  (install once with `python scripts/setup_hooks.py`). The deterministic
+  `python scripts/bump.py` computes the next version from commit prefixes
+  (`fix`=patch, `feat`=minor, `BREAKING CHANGE`/`!`=major) — **never let an LLM pick the
+  bump.** The pure logic lives in `scripts/release/` (tested in `tests/release/`); git I/O
+  is isolated in `scripts/release/gitio.py`. **Two records, two audiences:** git history is
+  the technical record; `CHANGELOG.md` is plain-language release notes for non-technical
+  users (also shown via the launcher's "What's new" dialog). The changelog *prose* is the
+  only LLM-assisted step — draft it with the `/release-notes` command, and **never commit
+  it unreviewed**; accuracy over flattery (don't invent user benefits a commit doesn't
+  support).
 ```

README.md

@@ -64,6 +64,45 @@ A green `pytest` and a clean `ruff` are both part of "done" here.
 & "C:\Program Files (x86)\Inno Setup 6\ISCC.exe" packaging\installer.iss
 ```
 
+## Versioning & releases
+
+The suite uses [Semantic Versioning](https://semver.org/) (`MAJOR.MINOR.PATCH`). There
+are **two records of change, with different audiences**:
+
+- **Git history** — the technical record. Every commit uses the
+  [Conventional Commit](https://www.conventionalcommits.org/) format `<type>: <description>`.
+- **[`CHANGELOG.md`](CHANGELOG.md)** — the human-facing record: plain-language release
+  notes for the (non-technical) people who use the app. It's also shown in-app via the
+  **What's new** button on the start page.
+
+| Commit type | Meaning | Version bump | In changelog? |
+|---|---|---|---|
+| `feat` | A new user-facing capability | **minor** | Yes (Added / Changed) |
+| `fix` | A bug fix | **patch** | Yes (Fixed) |
+| `feat!` / `BREAKING CHANGE:` in body | Removes or breaks existing behavior | **major** | Yes (Changed / Removed) |
+| `docs`, `style`, `refactor`, `perf`, `test`, `build`, `ci`, `chore`, `revert` | Internal work | none | Collapsed to one "maintenance" line, or dropped |
+
+```powershell
+# One-time on a fresh clone: install the commit-message validation hook
+.venv\Scripts\python scripts\setup_hooks.py
+
+# Bump the version (deterministic; edits pyproject.toml only). --dry-run to preview.
+.venv\Scripts\python scripts\bump.py --dry-run
+.venv\Scripts\python scripts\bump.py            # auto-detect from commits
+.venv\Scripts\python scripts\bump.py --minor    # or force a bump level
+
+# Draft release notes: in Claude Code run  /release-notes  (collects commits, drafts
+# plain-language entries for your review, and only writes CHANGELOG.md once approved).
+# Under the hood it calls:
+.venv\Scripts\python scripts\release_notes.py --json
+```
+
+The version string lives in **one place** — `[project] version` in `pyproject.toml`;
+`cim_suite.__version__` reads from it. The bump level is computed from commit prefixes,
+never by an LLM. The changelog *prose* is the only LLM-assisted step and is never
+committed without review. Releases start from the last `vX.Y.Z` git tag (or a
+`--baseline <rev>` you pass when there's no tag yet).
+
 ## Architecture
 
 Five strictly-ordered layers. The protocol core is **pure** (no I/O, no Qt) and the
@@ -105,6 +144,7 @@ UI edit → controller.set_* → encode → transport.write
 | [`docs/DESIGN-SYSTEM.md`](docs/DESIGN-SYSTEM.md) | Suite-wide visual standard |
 | [`docs/EXPORT.md`](docs/EXPORT.md) | `.xlsx` export engine + adoption checklist |
 | [`docs/VB6-MIGRATION-PLAYBOOK.md`](docs/VB6-MIGRATION-PLAYBOOK.md) | Reverse-engineering traps from the VB6 port |
+| [`CHANGELOG.md`](CHANGELOG.md) | Human-facing release notes (see _Versioning & releases_ above) |
 
 ## License
 

cim_suite/__init__.py

@@ -1,3 +1,64 @@
 """CIMTechniques Service Suite — unified desktop suite of instrument service tools."""
 
-__version__ = "0.1.0"
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+
+def _candidate_pyprojects() -> list[Path]:
+    """Places pyproject.toml may live, in priority order (frozen bundle, then source)."""
+    candidates = []
+    meipass = getattr(sys, "_MEIPASS", None)
+    if meipass is not None:
+        candidates.append(Path(meipass) / "pyproject.toml")
+    candidates.append(Path(__file__).resolve().parent.parent / "pyproject.toml")
+    return candidates
+
+
+def _detect_version() -> str:
+    """Resolve the suite version from its single source of truth, ``pyproject.toml``.
+
+    A source checkout (incl. editable installs) reads the live file, so a
+    ``scripts/bump.py`` edit shows up immediately with no reinstall; the frozen build
+    bundles the same file (see packaging/suite.spec). A plain wheel install with no
+    pyproject alongside the package falls back to the baked-in distribution metadata.
+    """
+    for pyproject in _candidate_pyprojects():
+        if pyproject.is_file():
+            try:
+                import tomllib
+
+                return tomllib.loads(pyproject.read_text("utf-8"))["project"]["version"]
+            except Exception:  # pragma: no cover - malformed pyproject falls through
+                pass
+    try:
+        from importlib.metadata import PackageNotFoundError, version
+
+        return version("cim-service-suite")
+    except PackageNotFoundError:  # pragma: no cover - not installed and no pyproject
+        return "0.0.0"
+
+
+__version__ = _detect_version()
+
+
+def changelog_path() -> Path | None:
+    """Locate the bundled ``CHANGELOG.md`` (repo root in source, bundle dir when frozen)."""
+    candidates = []
+    meipass = getattr(sys, "_MEIPASS", None)
+    if meipass is not None:
+        candidates.append(Path(meipass) / "CHANGELOG.md")
+    candidates.append(Path(__file__).resolve().parent.parent / "CHANGELOG.md")
+    for path in candidates:
+        if path.is_file():
+            return path
+    return None
+
+
+def changelog_markdown() -> str:
+    """The release notes as markdown, or a friendly placeholder if none is bundled."""
+    path = changelog_path()
+    if path is None:
+        return "# Changelog\n\nNo release notes are available in this build."
+    return path.read_text("utf-8")

cim_suite/core/ui/theme/stylesheet.py

@@ -371,6 +371,24 @@ QLabel#LauncherHeading {{
     font-weight: 900;
     padding: {S.LG}px {S.XS}px {S.SM}px {S.XS}px;
 }}
+QLabel#LauncherVersion {{
+    color: {C.TEXT_MUTED};
+    font-size: {T.SMALL_PT}pt;
+    font-weight: 700;
+    padding-right: {S.SM}px;
+}}
+QPushButton#WhatsNewButton {{
+    background-color: transparent;
+    color: {C.ACCENT};
+    border: 1px solid {C.ACCENT_SOFT_LINE};
+    border-radius: {R.MD}px;
+    padding: {S.XS}px {S.MD}px;
+    font-weight: 700;
+}}
+QPushButton#WhatsNewButton:hover {{
+    background-color: {C.ACCENT_SOFT};
+    border-color: {C.ACCENT};
+}}
 QFrame#ModuleCard {{
     background-color: {C.BG_SURFACE};
     border: 1px solid {C.BORDER};

cim_suite/modules/da07/__init__.py

@@ -1,3 +1,5 @@
 """DA-07 ("eLink") Monitoring Station Service Tool — modern rebuild."""
 
-__version__ = "3.0.0"
+from cim_suite import __version__  # one suite-wide version (single-sourced in pyproject)
+
+__all__ = ["__version__"]

cim_suite/modules/da12/__init__.py

@@ -1,3 +1,5 @@
 """DA-12 Monitoring Station Service Tool — modern rebuild."""
 
-__version__ = "3.0.0"
+from cim_suite import __version__  # one suite-wide version (single-sourced in pyproject)
+
+__all__ = ["__version__"]

cim_suite/modules/iomodbus/__init__.py

@@ -4,4 +4,6 @@ A config-driven Modbus RTU master (rebuild of the legacy VB6 ``IOModbus.exe``).
 ``docs/superpowers/specs/2026-06-03-iomodbus-service-tool-rebuild-design.md``.
 """
 
-__version__ = "3.0.0"
+from cim_suite import __version__  # one suite-wide version (single-sourced in pyproject)
+
+__all__ = ["__version__"]

cim_suite/shell/launcher.py

@@ -12,6 +12,7 @@ from PySide6.QtCore import Qt, Signal
 from PySide6.QtWidgets import (
     QFrame,
     QGridLayout,
+    QHBoxLayout,
     QLabel,
     QPushButton,
     QScrollArea,
@@ -19,11 +20,13 @@ from PySide6.QtWidgets import (
     QWidget,
 )
 
+import cim_suite
 from cim_suite.core.module import Module
 from cim_suite.core.transport.port_scan import DetectedPort, scan_ports
 from cim_suite.core.ui.theme import Space
 
 from .cable_panel import CablePanel
+from .whats_new import WhatsNewDialog
 
 _COLUMNS = 3
 
@@ -87,9 +90,21 @@ class LauncherView(QScrollArea):
         outer.setContentsMargins(Space.XL, Space.LG, Space.XL, Space.XL)
         outer.setSpacing(Space.MD)
 
+        header = QHBoxLayout()
         heading = QLabel("CIMTechniques Service Suite")
         heading.setObjectName("LauncherHeading")
-        outer.addWidget(heading)
+        header.addWidget(heading)
+        header.addStretch(1)
+
+        version = QLabel(f"v{cim_suite.__version__}")
+        version.setObjectName("LauncherVersion")
+        header.addWidget(version, alignment=Qt.AlignmentFlag.AlignVCenter)
+
+        self._whats_new_btn = QPushButton("What's new")
+        self._whats_new_btn.setObjectName("WhatsNewButton")
+        self._whats_new_btn.clicked.connect(self._show_whats_new)
+        header.addWidget(self._whats_new_btn, alignment=Qt.AlignmentFlag.AlignVCenter)
+        outer.addLayout(header)
 
         self._cable = CablePanel(include_simulator=include_simulator, scan_fn=scan_fn)
         self._cable.sourceChanged.connect(self._on_source_changed)
@@ -120,6 +135,9 @@ class LauncherView(QScrollArea):
         self._cable.set_scan_fn(self._scan_fn)
         return self._cable.rescan()
 
+    def _show_whats_new(self) -> None:
+        WhatsNewDialog(self).exec()
+
     def _on_source_changed(self, source: str) -> None:
         self._set_cards_enabled(bool(source))
 

cim_suite/shell/whats_new.py

@@ -0,0 +1,44 @@
+"""The "What's new" dialog: renders the bundled CHANGELOG.md as release notes.
+
+Plain-language notes for a non-technical audience live in CHANGELOG.md; this just
+displays them. The markdown is located/read by :mod:`cim_suite` so the same file
+works from a source checkout and a frozen build.
+"""
+
+from __future__ import annotations
+
+from PySide6.QtWidgets import (
+    QDialog,
+    QHBoxLayout,
+    QPushButton,
+    QTextBrowser,
+    QVBoxLayout,
+    QWidget,
+)
+
+import cim_suite
+from cim_suite.core.ui.theme import Space
+
+
+class WhatsNewDialog(QDialog):
+    def __init__(self, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self.setWindowTitle("What's new")
+        self.resize(580, 540)
+
+        layout = QVBoxLayout(self)
+        layout.setContentsMargins(Space.LG, Space.LG, Space.LG, Space.LG)
+        layout.setSpacing(Space.MD)
+
+        self.notes = QTextBrowser()
+        self.notes.setOpenExternalLinks(True)
+        self.notes.setMarkdown(cim_suite.changelog_markdown())
+        layout.addWidget(self.notes)
+
+        buttons = QHBoxLayout()
+        buttons.addStretch(1)
+        close = QPushButton("Close")
+        close.setProperty("variant", "primary")
+        close.clicked.connect(self.accept)
+        buttons.addWidget(close)
+        layout.addLayout(buttons)

packaging/suite.spec

@@ -25,6 +25,11 @@ _font_src = os.path.join(_repo_root, "cim_suite", "core", "ui", "theme", "fonts"
 # (importlib.resources) can read it.
 _iomodbus_res = os.path.join(_repo_root, "cim_suite", "modules", "iomodbus", "resources")
 
+# Version is single-sourced from pyproject.toml and the "What's new" dialog renders
+# CHANGELOG.md; both are read at runtime from the bundle root (sys._MEIPASS).
+_pyproject = os.path.join(_repo_root, "pyproject.toml")
+_changelog = os.path.join(_repo_root, "CHANGELOG.md")
+
 a = Analysis(
     [os.path.join(SPECPATH, "suite_launcher.py")],
     pathex=[_repo_root],
@@ -32,6 +37,8 @@ a = Analysis(
     datas=[
         (_font_src, os.path.join("cim_suite", "core", "ui", "theme", "fonts")),
         (_iomodbus_res, os.path.join("cim_suite", "modules", "iomodbus", "resources")),
+        (_pyproject, "."),
+        (_changelog, "."),
     ],
     hiddenimports=["serial.tools.list_ports", "openpyxl", "PySide6.QtCharts"],
     hookspath=[],

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "cim-service-suite"
-version = "3.0.0"
+version = "1.0.0"
 description = "DA-12 Monitoring Station Service Tool (modern rebuild)"
 requires-python = ">=3.11"
 dependencies = ["PySide6>=6.7", "pyserial>=3.5", "openpyxl>=3.1"]

scripts/bump.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python
+"""Deterministically bump the suite version from Conventional Commit history.
+
+The bump type is computed from commit prefixes (fix=patch, feat=minor, a
+``BREAKING CHANGE`` body / ``!`` marker = major) unless overridden. The version
+lives in exactly one place — ``[project] version`` in pyproject.toml — and this is
+the only writer. An LLM is never asked to decide the bump.
+
+    python scripts/bump.py                 # auto-detect from commits, write pyproject
+    python scripts/bump.py --dry-run       # show what it would do, change nothing
+    python scripts/bump.py --minor         # force a minor bump
+    python scripts/bump.py --baseline <rev>  # range start when there is no version tag
+"""
+
+from __future__ import annotations
+
+import argparse
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+
+from release import repo  # noqa: E402
+from release.versioning import BumpKind, set_version  # noqa: E402
+
+
+def _override(args: argparse.Namespace) -> BumpKind | None:
+    for kind in ("major", "minor", "patch"):
+        if getattr(args, kind):
+            return kind  # type: ignore[return-value]
+    return None
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument("--major", action="store_true", help="force a major bump")
+    group.add_argument("--minor", action="store_true", help="force a minor bump")
+    group.add_argument("--patch", action="store_true", help="force a patch bump")
+    parser.add_argument("--dry-run", action="store_true", help="print, do not write")
+    parser.add_argument("--baseline", help="range start commit/tag when no version tag exists")
+    args = parser.parse_args(argv)
+
+    plan = repo.gather(baseline=args.baseline)
+    rng = plan.range_spec or "(all commits)"
+    print(f"Current version: {plan.current}")
+    print(f"Scanning {rng}: {len(plan.commits)} commit(s).")
+
+    bump = _override(args) or plan.detected_bump
+    if bump is None:
+        print(
+            "No releasable commits (no feat/fix/breaking) in range.\n"
+            "Nothing to bump — pass --patch/--minor/--major to force."
+        )
+        return 0
+
+    new_version = plan.current.bump(bump)
+    source = "forced" if _override(args) else "detected"
+    print(f"Bump ({source}): {bump}  ->  {new_version}")
+
+    if args.dry_run:
+        print("Dry run - pyproject.toml not modified.")
+        return 0
+
+    repo.PYPROJECT.write_text(set_version(repo.PYPROJECT.read_text("utf-8"), str(new_version)))
+    print(f"Updated {repo.PYPROJECT.name} to version {new_version}.")
+    print(
+        f"Next: draft release notes (/release-notes), review CHANGELOG.md, then\n"
+        f"      git commit -am 'chore: release {new_version}' && git tag v{new_version}"
+    )
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/commit_msg_hook.py

@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+"""commit-msg hook body: reject messages that aren't ``<type>: <description>``.
+
+Invoked by ``.githooks/commit-msg`` with the path to the commit message file.
+Validation logic lives in :mod:`release.commits` so it is unit-tested.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+
+from release.commits import KNOWN_TYPES, validate_commit_message  # noqa: E402
+
+
+def main(argv: list[str]) -> int:
+    if len(argv) < 2:
+        return 0
+    message = Path(argv[1]).read_text("utf-8")
+    error = validate_commit_message(message)
+    if error is None:
+        return 0
+    indented = "\n  ".join(error.splitlines())
+    sys.stderr.write(
+        "\n  x Commit rejected: invalid commit message.\n\n"
+        f"  {indented}\n\n"
+        f"  Format : <type>(<optional scope>): <description>\n"
+        f"  Types  : {', '.join(KNOWN_TYPES)}\n"
+        "  Example: feat(da12): add live sensor sparkline\n\n"
+    )
+    return 1
+
+
+if __name__ == "__main__":
+    raise SystemExit(main(sys.argv))

scripts/release/__init__.py

@@ -0,0 +1,8 @@
+"""Pure, testable logic for the suite's versioning + changelog tooling.
+
+This package holds the deterministic backbone (semver arithmetic, commit parsing,
+range resolution, classification) used by the ``scripts/*.py`` CLIs and the
+``.githooks/commit-msg`` hook. It is import-only: no side effects, no git I/O.
+The git plumbing lives in :mod:`release.gitio`; the prose summarization is a
+human+LLM step that never lives in code.
+"""

scripts/release/commits.py

@@ -0,0 +1,154 @@
+"""Conventional-commit parsing, bump detection, range resolution, classification.
+
+All pure functions over plain data — the git plumbing that produces ``ParsedCommit``
+records lives in :mod:`release.gitio`.
+"""
+
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass
+
+from .versioning import BumpKind, Version
+
+# The commit types we recognise. feat/fix are user-visible; the rest are internal
+# noise the changelog collapses. Unknown prefixes (e.g. a stray "polish:") are
+# rejected by the commit-msg hook and treated as internal if they slip through.
+USER_VISIBLE_TYPES = ("feat", "fix")
+INTERNAL_TYPES = (
+    "docs",
+    "style",
+    "refactor",
+    "perf",
+    "test",
+    "build",
+    "ci",
+    "chore",
+    "revert",
+)
+KNOWN_TYPES = (*USER_VISIBLE_TYPES, *INTERNAL_TYPES)
+
+_SUBJECT_RE = re.compile(
+    r"^(?P<type>[a-z]+)(?:\((?P<scope>[^)]+)\))?(?P<bang>!)?:\s*(?P<desc>.*)$"
+)
+_BREAKING_BODY_RE = re.compile(r"(?m)^BREAKING[ -]CHANGE:")
+# Subjects git generates itself, which are not Conventional Commits but are valid.
+_MERGE_RE = re.compile(r"^Merge ")
+_REVERT_RE = re.compile(r'^Revert "')
+_AUTOSQUASH_RE = re.compile(r"^(fixup|squash|amend)! ")
+
+
+@dataclass(frozen=True)
+class ParsedCommit:
+    """One commit decomposed into Conventional-Commit parts.
+
+    ``type`` is ``None`` for a non-conventional subject (e.g. a merge commit).
+    """
+
+    sha: str
+    type: str | None
+    scope: str | None
+    breaking: bool
+    description: str
+    body: str
+
+
+def parse_commit(sha: str, subject: str, body: str = "") -> ParsedCommit:
+    """Decompose a commit subject/body into a :class:`ParsedCommit`."""
+    breaking = bool(_BREAKING_BODY_RE.search(body))
+    m = _SUBJECT_RE.match(subject)
+    if m is None or m.group("type") not in KNOWN_TYPES:
+        return ParsedCommit(sha, None, None, breaking, subject.strip(), body)
+    return ParsedCommit(
+        sha=sha,
+        type=m.group("type"),
+        scope=m.group("scope"),
+        breaking=breaking or bool(m.group("bang")),
+        description=m.group("desc").strip(),
+        body=body,
+    )
+
+
+def determine_bump(commits: list[ParsedCommit]) -> BumpKind | None:
+    """Highest-priority bump implied by the commits, or ``None`` if none are releasable."""
+    if any(c.breaking for c in commits):
+        return "major"
+    if any(c.type == "feat" for c in commits):
+        return "minor"
+    if any(c.type == "fix" for c in commits):
+        return "patch"
+    return None
+
+
+_TAG_RE = re.compile(r"^v(\d+)\.(\d+)\.(\d+)$")
+
+
+def last_version_tag(tags: list[str]) -> str | None:
+    """The highest ``vX.Y.Z`` tag by semver, or ``None`` if there are none."""
+    versioned = [t for t in tags if _TAG_RE.match(t)]
+    if not versioned:
+        return None
+    return max(versioned, key=lambda t: Version.parse(t[1:]))
+
+
+def commit_range(*, last_tag: str | None, baseline: str | None) -> str | None:
+    """Git revision range to scan. ``None`` means 'all commits'."""
+    start = last_tag or baseline
+    if start is None:
+        return None
+    return f"{start}..HEAD"
+
+
+@dataclass(frozen=True)
+class ReleaseDigest:
+    """The user-review material for one release: visible changes + collapsed internals."""
+
+    features: list[ParsedCommit]
+    fixes: list[ParsedCommit]
+    breaking: list[ParsedCommit]
+    internal: list[ParsedCommit]
+
+
+def build_digest(commits: list[ParsedCommit]) -> ReleaseDigest:
+    """Split commits into feat / fix / breaking / internal buckets for summarization."""
+    return ReleaseDigest(
+        features=[c for c in commits if c.type == "feat"],
+        fixes=[c for c in commits if c.type == "fix"],
+        breaking=[c for c in commits if c.breaking],
+        internal=[c for c in commits if c.type not in USER_VISIBLE_TYPES],
+    )
+
+
+def validate_commit_message(message: str) -> str | None:
+    """Return an error string if ``message`` is not a valid commit subject, else ``None``."""
+    subject = ""
+    for line in message.splitlines():
+        if line.startswith("#"):
+            continue  # git comment lines (and the editor template) are not the subject
+        if line.strip():
+            subject = line.rstrip()
+            break
+
+    if not subject:
+        return "empty commit message"
+    if (
+        _MERGE_RE.match(subject)
+        or _REVERT_RE.match(subject)
+        or _AUTOSQUASH_RE.match(subject)
+    ):
+        return None  # git-generated subjects (merge/revert/autosquash) are allowed through
+
+    m = _SUBJECT_RE.match(subject)
+    if m is None:
+        return (
+            f"commit subject must be '<type>: <description>' (got: {subject!r}).\n"
+            f"  Valid types: {', '.join(KNOWN_TYPES)}"
+        )
+    if m.group("type") not in KNOWN_TYPES:
+        return (
+            f"unknown commit type {m.group('type')!r}.\n"
+            f"  Valid types: {', '.join(KNOWN_TYPES)}"
+        )
+    if not m.group("desc").strip():
+        return "commit description is empty after the ':'"
+    return None

scripts/release/gitio.py

@@ -0,0 +1,50 @@
+"""Thin git plumbing: list tags, read commits in a range. The only impure module."""
+
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+
+from .commits import ParsedCommit, parse_commit
+
+# Field/record separators unlikely to appear in commit text.
+_FS = "\x1f"
+_RS = "\x1e"
+
+
+def _git(args: list[str], cwd: Path | str | None) -> str:
+    result = subprocess.run(
+        ["git", *args],
+        cwd=cwd,
+        check=True,
+        capture_output=True,
+        text=True,
+        encoding="utf-8",
+    )
+    return result.stdout
+
+
+def list_tags(*, cwd: Path | str | None = None) -> list[str]:
+    """All tag names in the repo."""
+    out = _git(["tag", "--list"], cwd)
+    return [line.strip() for line in out.splitlines() if line.strip()]
+
+
+def commits_in_range(
+    range_spec: str | None, *, cwd: Path | str | None = None
+) -> list[ParsedCommit]:
+    """Parsed commits in ``range_spec`` (newest first). ``None`` means all commits."""
+    fmt = f"%H{_FS}%s{_FS}%b{_RS}"
+    args = ["log", f"--pretty=format:{fmt}"]
+    if range_spec:
+        args.append(range_spec)
+    out = _git(args, cwd)
+
+    commits: list[ParsedCommit] = []
+    for record in out.split(_RS):
+        record = record.strip("\n")
+        if not record:
+            continue
+        sha, subject, body = record.split(_FS)
+        commits.append(parse_commit(sha, subject, body))
+    return commits

scripts/release/repo.py

@@ -0,0 +1,40 @@
+"""Shared glue between the pure logic and the on-disk repo for the CLI entry points."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from pathlib import Path
+
+from . import gitio
+from .commits import ParsedCommit, commit_range, determine_bump, last_version_tag
+from .versioning import BumpKind, Version, read_version
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+PYPROJECT = REPO_ROOT / "pyproject.toml"
+
+
+@dataclass(frozen=True)
+class ReleasePlan:
+    """Everything the bump/changelog CLIs need, computed once from the repo state."""
+
+    current: Version
+    range_spec: str | None
+    commits: list[ParsedCommit]
+    detected_bump: BumpKind | None
+    baseline: str | None
+
+
+def gather(baseline: str | None = None) -> ReleasePlan:
+    """Read the current version and the commits since the last tag (or baseline)."""
+    current = Version.parse(read_version(PYPROJECT.read_text("utf-8")))
+    tags = gitio.list_tags(cwd=REPO_ROOT)
+    last_tag = last_version_tag(tags)
+    range_spec = commit_range(last_tag=last_tag, baseline=baseline)
+    commits = gitio.commits_in_range(range_spec, cwd=REPO_ROOT)
+    return ReleasePlan(
+        current=current,
+        range_spec=range_spec,
+        commits=commits,
+        detected_bump=determine_bump(commits),
+        baseline=baseline,
+    )

scripts/release/versioning.py

@@ -0,0 +1,67 @@
+"""Semver value object and the pyproject version single-source read/write."""
+
+from __future__ import annotations
+
+import re
+import tomllib
+from dataclasses import dataclass
+from typing import Literal
+
+BumpKind = Literal["major", "minor", "patch"]
+
+_SEMVER_RE = re.compile(r"^(\d+)\.(\d+)\.(\d+)$")
+
+
+@dataclass(frozen=True, order=True)
+class Version:
+    """A semantic version ``major.minor.patch`` (no pre-release/build metadata)."""
+
+    major: int
+    minor: int
+    patch: int
+
+    @classmethod
+    def parse(cls, text: str) -> "Version":
+        m = _SEMVER_RE.match(text.strip())
+        if m is None:
+            raise ValueError(f"not a MAJOR.MINOR.PATCH version: {text!r}")
+        return cls(int(m.group(1)), int(m.group(2)), int(m.group(3)))
+
+    def __str__(self) -> str:
+        return f"{self.major}.{self.minor}.{self.patch}"
+
+    def bump(self, kind: BumpKind) -> "Version":
+        if kind == "major":
+            return Version(self.major + 1, 0, 0)
+        if kind == "minor":
+            return Version(self.major, self.minor + 1, 0)
+        if kind == "patch":
+            return Version(self.major, self.minor, self.patch + 1)
+        raise ValueError(f"unknown bump kind: {kind!r}")
+
+
+# The [project] table header up to the next table header or end of text.
+_PROJECT_TABLE_RE = re.compile(r"(?ms)^\[project\]\s*$.*?(?=^\[|\Z)")
+_VERSION_LINE_RE = re.compile(r'(?m)^(version\s*=\s*")([^"]*)(")')
+
+
+def read_version(pyproject_text: str) -> str:
+    """Return the ``[project] version`` string from pyproject.toml text."""
+    return tomllib.loads(pyproject_text)["project"]["version"]
+
+
+def set_version(pyproject_text: str, new_version: str) -> str:
+    """Return pyproject.toml text with the ``[project] version`` set to ``new_version``.
+
+    Only the version line inside the ``[project]`` table is touched; identical-looking
+    lines in other tables (e.g. ``[tool.x] version = ...``) are left alone, and all
+    surrounding formatting/comments are preserved.
+    """
+    Version.parse(new_version)  # reject garbage before we rewrite the file
+
+    table = _PROJECT_TABLE_RE.search(pyproject_text)
+    if table is None or not _VERSION_LINE_RE.search(table.group(0)):
+        raise ValueError("no [project] version line found in pyproject.toml")
+
+    new_table = _VERSION_LINE_RE.sub(rf"\g<1>{new_version}\g<3>", table.group(0), count=1)
+    return pyproject_text[: table.start()] + new_table + pyproject_text[table.end() :]

scripts/release_notes.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+"""Collect commits since the last release and emit a digest for changelog drafting.
+
+This produces the STRUCTURED INPUT for the human + Claude changelog step. It never
+writes CHANGELOG.md and never invents prose — it just buckets commits into
+user-visible features/fixes/breaking changes vs. collapsible internal work, using the
+same range logic as the bump script. The plain-language summary is drafted by Claude
+from this digest and reviewed before it lands (see ``.claude/commands/release-notes.md``).
+
+    python scripts/release_notes.py              # human-readable digest
+    python scripts/release_notes.py --json        # machine-readable digest (for Claude)
+    python scripts/release_notes.py --baseline <rev>
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+
+from release import repo  # noqa: E402
+from release.commits import ParsedCommit, build_digest  # noqa: E402
+
+
+def _commit_dict(c: ParsedCommit) -> dict[str, object]:
+    return {
+        "sha": c.sha[:8],
+        "type": c.type,
+        "scope": c.scope,
+        "breaking": c.breaking,
+        "description": c.description,
+    }
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--json", action="store_true", help="emit JSON for tooling/Claude")
+    parser.add_argument("--baseline", help="range start commit/tag when no version tag exists")
+    args = parser.parse_args(argv)
+
+    plan = repo.gather(baseline=args.baseline)
+    digest = build_digest(plan.commits)
+    bump = plan.detected_bump or "patch"
+    suggested = plan.current.bump(bump)
+
+    if args.json:
+        payload = {
+            "current_version": str(plan.current),
+            "suggested_version": str(suggested),
+            "suggested_bump": bump,
+            "detected_bump": plan.detected_bump,
+            "range": plan.range_spec,
+            "features": [_commit_dict(c) for c in digest.features],
+            "fixes": [_commit_dict(c) for c in digest.fixes],
+            "breaking": [_commit_dict(c) for c in digest.breaking],
+            "internal_count": len(digest.internal),
+            "internal_types": sorted({c.type or "other" for c in digest.internal}),
+        }
+        print(json.dumps(payload, indent=2))
+        return 0
+
+    rng = plan.range_spec or "(all commits)"
+    print(f"# Release digest  ({plan.current} -> {suggested}, {bump})")
+    print(f"Range: {rng}   Commits: {len(plan.commits)}\n")
+    for title, items in (
+        ("Breaking changes", digest.breaking),
+        ("Features (feat)", digest.features),
+        ("Fixes (fix)", digest.fixes),
+    ):
+        print(f"## {title} ({len(items)})")
+        for c in items:
+            scope = f"({c.scope})" if c.scope else ""
+            print(f"  - {c.sha[:8]} {c.type}{scope}: {c.description}")
+        print()
+    types = sorted({c.type or "other" for c in digest.internal})
+    print(f"## Internal (collapse to one line): {len(digest.internal)} commit(s) {types}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/setup_hooks.py

@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+"""One-time install of the repo's git hooks on a fresh clone.
+
+Points git at the version-controlled ``.githooks`` directory so the commit-msg
+validator runs without copying anything into ``.git``.
+
+    python scripts/setup_hooks.py
+"""
+
+from __future__ import annotations
+
+import os
+import stat
+import subprocess
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+
+
+def main() -> int:
+    subprocess.run(["git", "config", "core.hooksPath", ".githooks"], cwd=ROOT, check=True)
+
+    hook = ROOT / ".githooks" / "commit-msg"
+    if hook.is_file() and os.name != "nt":
+        hook.chmod(hook.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
+
+    print("Git hooks installed: core.hooksPath -> .githooks")
+    print("Commit messages will now be validated against the Conventional Commit format.")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

tests/release/conftest.py

@@ -0,0 +1,14 @@
+"""Make the dev-only ``scripts/release`` package importable as ``release``.
+
+It is deliberately not part of the shipped ``cim_suite`` wheel, so it is not on
+``sys.path`` via the editable install. Prepend the repo's ``scripts`` dir here.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+_SCRIPTS = Path(__file__).resolve().parents[2] / "scripts"
+if str(_SCRIPTS) not in sys.path:
+    sys.path.insert(0, str(_SCRIPTS))

tests/release/test_commits.py

@@ -0,0 +1,173 @@
+"""Tests for commit parsing, bump detection, range resolution, and classification."""
+
+from __future__ import annotations
+
+from release.commits import (
+    ParsedCommit,
+    build_digest,
+    commit_range,
+    determine_bump,
+    last_version_tag,
+    parse_commit,
+    validate_commit_message,
+)
+
+
+# --- parse_commit ----------------------------------------------------------
+def test_parse_plain_type():
+    c = parse_commit("abc", "feat: add launcher")
+    assert c.type == "feat"
+    assert c.scope is None
+    assert c.breaking is False
+    assert c.description == "add launcher"
+
+
+def test_parse_with_scope():
+    c = parse_commit("abc", "fix(repository): stretch Value column")
+    assert c.type == "fix"
+    assert c.scope == "repository"
+    assert c.description == "stretch Value column"
+
+
+def test_parse_bang_marks_breaking():
+    c = parse_commit("abc", "feat(api)!: drop wireless sensors")
+    assert c.type == "feat"
+    assert c.scope == "api"
+    assert c.breaking is True
+
+
+def test_parse_breaking_change_in_body():
+    c = parse_commit("abc", "refactor: rework transport", body="BREAKING CHANGE: ports moved")
+    assert c.breaking is True
+
+
+def test_parse_breaking_change_hyphen_variant():
+    c = parse_commit("abc", "feat: x", body="BREAKING-CHANGE: y")
+    assert c.breaking is True
+
+
+def test_parse_non_conventional_subject():
+    c = parse_commit("abc", "Merge branch 'feat/foo' into main")
+    assert c.type is None
+    assert c.breaking is False
+    assert c.description == "Merge branch 'feat/foo' into main"
+
+
+# --- determine_bump --------------------------------------------------------
+def test_bump_breaking_wins():
+    commits = [
+        parse_commit("1", "feat: a"),
+        parse_commit("2", "fix: b"),
+        parse_commit("3", "feat!: c"),
+    ]
+    assert determine_bump(commits) == "major"
+
+
+def test_bump_feat_over_fix():
+    commits = [parse_commit("1", "fix: a"), parse_commit("2", "feat: b")]
+    assert determine_bump(commits) == "minor"
+
+
+def test_bump_fix_only():
+    commits = [parse_commit("1", "fix: a"), parse_commit("2", "docs: b")]
+    assert determine_bump(commits) == "patch"
+
+
+def test_bump_none_when_no_releasable_commits():
+    commits = [parse_commit("1", "docs: a"), parse_commit("2", "chore: b")]
+    assert determine_bump(commits) is None
+
+
+def test_bump_none_for_empty():
+    assert determine_bump([]) is None
+
+
+# --- last_version_tag ------------------------------------------------------
+def test_last_version_tag_picks_highest_semver():
+    tags = ["v1.0.0", "v1.2.0", "v1.10.0", "v1.9.0"]
+    assert last_version_tag(tags) == "v1.10.0"
+
+
+def test_last_version_tag_ignores_non_version_tags():
+    tags = ["baseline", "v1.0.0", "release-candidate", "not-a-version"]
+    assert last_version_tag(tags) == "v1.0.0"
+
+
+def test_last_version_tag_none_when_empty():
+    assert last_version_tag([]) is None
+    assert last_version_tag(["nightly", "stable"]) is None
+
+
+# --- commit_range ----------------------------------------------------------
+def test_range_prefers_last_tag():
+    assert commit_range(last_tag="v1.2.0", baseline="abc123") == "v1.2.0..HEAD"
+
+
+def test_range_falls_back_to_baseline():
+    assert commit_range(last_tag=None, baseline="abc123") == "abc123..HEAD"
+
+
+def test_range_all_commits_when_neither():
+    assert commit_range(last_tag=None, baseline=None) is None
+
+
+# --- build_digest ----------------------------------------------------------
+def _commits() -> list[ParsedCommit]:
+    return [
+        parse_commit("1", "feat: new screen"),
+        parse_commit("2", "fix: crash on open"),
+        parse_commit("3", "feat!: remove old mode"),
+        parse_commit("4", "refactor: tidy"),
+        parse_commit("5", "test: add coverage"),
+        parse_commit("6", "Merge branch 'x'"),
+    ]
+
+
+def test_digest_buckets():
+    d = build_digest(_commits())
+    assert [c.sha for c in d.features] == ["1", "3"]
+    assert [c.sha for c in d.fixes] == ["2"]
+    assert [c.sha for c in d.breaking] == ["3"]
+    # refactor, test, and the merge all collapse into internal.
+    assert [c.sha for c in d.internal] == ["4", "5", "6"]
+
+
+# --- validate_commit_message ----------------------------------------------
+def test_validate_accepts_conventional():
+    assert validate_commit_message("feat: add thing") is None
+    assert validate_commit_message("fix(scope): bug") is None
+    assert validate_commit_message("feat(api)!: breaking") is None
+
+
+def test_validate_accepts_merge_and_revert():
+    assert validate_commit_message("Merge branch 'main' into feat/x") is None
+    assert validate_commit_message('Revert "feat: add thing"') is None
+
+
+def test_validate_accepts_fixup_and_squash():
+    # git commit --fixup/--squash generate these; rejecting them breaks autosquash.
+    assert validate_commit_message("fixup! feat: add thing") is None
+    assert validate_commit_message("squash! fix: the bug") is None
+    assert validate_commit_message("amend! feat: add thing") is None
+
+
+def test_validate_rejects_missing_type():
+    err = validate_commit_message("add a thing")
+    assert err is not None
+    assert "type" in err.lower()
+
+
+def test_validate_rejects_unknown_type():
+    err = validate_commit_message("feet: typo in type")
+    assert err is not None
+
+
+def test_validate_rejects_empty_description():
+    err = validate_commit_message("feat: ")
+    assert err is not None
+
+
+def test_validate_ignores_comment_lines():
+    # git passes the whole COMMIT_EDITMSG; comment lines must not be validated.
+    msg = "feat: real subject\n\n# Please enter the commit message\n# comment"
+    assert validate_commit_message(msg) is None

tests/release/test_gitio.py

@@ -0,0 +1,61 @@
+"""Integration tests for the git plumbing, against throwaway temp repos."""
+
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+
+import pytest
+
+from release import gitio
+
+
+def _git(repo: Path, *args: str) -> None:
+    subprocess.run(["git", *args], cwd=repo, check=True, capture_output=True, text=True)
+
+
+@pytest.fixture
+def repo(tmp_path: Path) -> Path:
+    r = tmp_path / "repo"
+    r.mkdir()
+    _git(r, "init", "-q")
+    _git(r, "config", "user.email", "t@t.t")
+    _git(r, "config", "user.name", "t")
+    return r
+
+
+def _commit(repo: Path, subject: str, body: str = "") -> None:
+    (repo / "f.txt").write_text(subject)
+    _git(repo, "add", "-A")
+    msg = subject if not body else f"{subject}\n\n{body}"
+    _git(repo, "commit", "-q", "-m", msg)
+
+
+def test_list_tags(repo: Path):
+    _commit(repo, "feat: one")
+    _git(repo, "tag", "v1.0.0")
+    _git(repo, "tag", "baseline")
+    assert set(gitio.list_tags(cwd=repo)) == {"v1.0.0", "baseline"}
+
+
+def test_commits_in_range_all(repo: Path):
+    _commit(repo, "feat: one")
+    _commit(repo, "fix: two")
+    commits = gitio.commits_in_range(None, cwd=repo)
+    # Newest first, parsed.
+    assert [c.type for c in commits] == ["fix", "feat"]
+    assert [c.description for c in commits] == ["two", "one"]
+
+
+def test_commits_in_range_since_tag(repo: Path):
+    _commit(repo, "feat: before")
+    _git(repo, "tag", "v1.0.0")
+    _commit(repo, "fix: after")
+    commits = gitio.commits_in_range("v1.0.0..HEAD", cwd=repo)
+    assert [c.description for c in commits] == ["after"]
+
+
+def test_commits_in_range_parses_body_breaking(repo: Path):
+    _commit(repo, "refactor: rework", body="BREAKING CHANGE: moved ports")
+    commits = gitio.commits_in_range(None, cwd=repo)
+    assert commits[0].breaking is True

tests/release/test_versioning.py

@@ -0,0 +1,92 @@
+"""Tests for the semver value object and the pyproject version single-source."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from release.versioning import Version, read_version, set_version
+
+_REPO_ROOT = Path(__file__).resolve().parents[2]
+
+
+def test_parse_roundtrip():
+    assert str(Version.parse("1.2.3")) == "1.2.3"
+    assert Version.parse("1.2.3") == Version(1, 2, 3)
+
+
+def test_parse_rejects_garbage():
+    with pytest.raises(ValueError):
+        Version.parse("1.2")
+    with pytest.raises(ValueError):
+        Version.parse("v1.2.3")  # the 'v' prefix is a tag concern, not a version string
+    with pytest.raises(ValueError):
+        Version.parse("1.2.x")
+
+
+def test_bump_patch():
+    assert Version(1, 2, 3).bump("patch") == Version(1, 2, 4)
+
+
+def test_bump_minor_resets_patch():
+    assert Version(1, 2, 3).bump("minor") == Version(1, 3, 0)
+
+
+def test_bump_major_resets_minor_and_patch():
+    assert Version(1, 2, 3).bump("major") == Version(2, 0, 0)
+
+
+def test_versions_are_ordered():
+    assert Version(1, 0, 0) < Version(1, 0, 1) < Version(1, 1, 0) < Version(2, 0, 0)
+
+
+PYPROJECT = """\
+[project]
+name = "cim-service-suite"
+version = "1.0.0"
+description = "x"
+requires-python = ">=3.11"
+
+[build-system]
+requires = ["setuptools>=68"]
+"""
+
+
+def test_read_version():
+    assert read_version(PYPROJECT) == "1.0.0"
+
+
+def test_set_version_changes_only_project_version():
+    out = set_version(PYPROJECT, "1.1.0")
+    assert read_version(out) == "1.1.0"
+    # Everything else is preserved verbatim.
+    assert 'name = "cim-service-suite"' in out
+    assert 'requires = ["setuptools>=68"]' in out
+    assert out.count('version = "') == 1
+
+
+def test_set_version_ignores_lookalike_version_in_other_table():
+    text = (
+        '[project]\nname = "x"\nversion = "1.0.0"\n\n'
+        '[tool.thing]\nversion = "9.9.9"\n'
+    )
+    out = set_version(text, "1.0.1")
+    assert read_version(out) == "1.0.1"
+    assert 'version = "9.9.9"' in out  # untouched
+
+
+def test_cim_suite_version_is_single_sourced_from_pyproject():
+    import cim_suite
+
+    pyproject = (_REPO_ROOT / "pyproject.toml").read_text("utf-8")
+    assert cim_suite.__version__ == read_version(pyproject)
+
+
+def test_modules_reexport_the_suite_version():
+    import cim_suite
+    from cim_suite.modules import da07, da12, iomodbus
+
+    assert da12.__version__ == cim_suite.__version__
+    assert da07.__version__ == cim_suite.__version__
+    assert iomodbus.__version__ == cim_suite.__version__

tests/shell/test_whats_new.py

@@ -0,0 +1,28 @@
+"""Launcher version badge + the What's-new release-notes dialog."""
+
+from __future__ import annotations
+
+from PySide6.QtWidgets import QLabel
+
+import cim_suite
+from cim_suite.modules.da12.module import Da12Module
+from cim_suite.shell.launcher import LauncherView
+from cim_suite.shell.whats_new import WhatsNewDialog
+
+
+def _scan_none(*, include_simulator=False):
+    return []
+
+
+def test_launcher_shows_suite_version(qtbot):
+    view = LauncherView([Da12Module(simulate=True)], scan_fn=_scan_none)
+    qtbot.addWidget(view)
+    texts = [w.text() for w in view.findChildren(QLabel)]
+    assert f"v{cim_suite.__version__}" in texts
+
+
+def test_whats_new_dialog_renders_changelog(qtbot):
+    dlg = WhatsNewDialog()
+    qtbot.addWidget(dlg)
+    rendered = dlg.notes.toPlainText()
+    assert rendered.strip()  # never empty (real changelog or a friendly placeholder)