feat: add changelog generation workflow to rebuild-nixos

Adds automated changelog draft generation as Phase 7 of rebuild:
- Detects commits since last CHANGELOG.md entry
- Categorizes by type (feat→Added, fix→Fixed, etc.)
- Interactive review/edit/append workflow
- Integrates with Keep a Changelog format

New files:
- scripts/generate-changelog-draft.sh - Generator script
- .claude/commands/changelog-update.md - Claude Code command

Also includes routine analytics and flake.lock updates.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: jacopone

.claude/commands/changelog-update.md

@@ -0,0 +1,114 @@
+---
+status: active
+created: 2025-12-11
+updated: 2025-12-11
+type: reference
+lifecycle: persistent
+description: Generate changelog draft from recent commits
+---
+
+# Changelog Update
+
+Generate a changelog draft from git commits since the last CHANGELOG.md entry.
+
+## Your Task
+
+1. **Run the generator script**:
+   ```bash
+   ./scripts/generate-changelog-draft.sh
+   ```
+
+2. **Review the output**:
+   - Verify the categorization makes sense (Added/Changed/Fixed)
+   - Check that test hints are accurate and runnable
+   - Look for any commits that were incorrectly filtered out
+
+3. **Enhance entries if needed**:
+   - Improve descriptions to be user-friendly (not just commit messages)
+   - Add better test commands where the heuristics failed
+   - Group related entries (e.g., multiple tools added together)
+
+4. **Present the draft to the user**:
+   Show the enhanced draft in a code block:
+   ```markdown
+   ## [YYYY-MM-DD]
+
+   ### Added
+   - Description with test hint
+
+   ### Changed
+   - Description
+
+   ### Fixed
+   - Description with test hint
+   ```
+
+5. **Ask for approval**:
+   - Options: Append to CHANGELOG.md, Edit first, Skip
+   - If approved, update the `[Unreleased]` section in CHANGELOG.md
+
+## Filtering Rules
+
+The script follows these rules (you should verify they make sense):
+
+| Type | Include? | Category |
+|------|----------|----------|
+| `feat:` | Always | Added |
+| `fix:` | Always | Fixed |
+| `perf:` | Always | Changed |
+| `chore:` | Only if packages.nix changed | Changed |
+| `refactor:` | Only if user-facing | Changed |
+| `docs:`, `ci:`, `test:` | Never | - |
+
+## Enhancement Guidelines
+
+When improving the raw output:
+
+**Good test hints** (specific, runnable):
+```
+(Test: `echo "hello" | wl-copy && wl-paste`)
+(Test: Connect Android device, run `adb devices`)
+(Test: Launch Kooha from application menu)
+```
+
+**Bad test hints** (vague, not actionable):
+```
+(Test: Verify it works)
+(Test: Check the feature)
+```
+
+**Good descriptions** (user-focused):
+```
+- `wl-clipboard` - Copy/paste in terminal for Wayland sessions
+- ADB support for Android development and debugging
+```
+
+**Bad descriptions** (developer-focused):
+```
+- add wl-clipboard and kooha, simplify fish config
+- enable ADB for Android development
+```
+
+## CHANGELOG.md Format
+
+Follow [Keep a Changelog](https://keepachangelog.com/en/1.0.0/):
+
+```markdown
+## [Unreleased]
+
+### Planned
+- (Future work items)
+
+---
+
+## [2025-12-11]
+
+### Added
+- New feature descriptions...
+```
+
+## Important
+
+- **NEVER auto-commit** - Always show draft and wait for approval
+- **Preserve existing content** - Only add to `[Unreleased]` section
+- **Date new entries** - When moving from Unreleased to dated section