chore: remove vibe-coding artifacts from tracking, sync notes and obsidian config

- Untrack .claude/launch.json (Claude Code config)
- Add .claude/, .mcp.json, CLAUDE.md, and AI-generated CSVs to .gitignore
- Add _notes/ vault (architecture, API, tasks, bugs, infra docs)
- Add .obsidian/ plugin/vault config (workspace state excluded)
- Sync CHANGELOG.md

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

_notes/08 - Meetings & Notes/Meeting Template.md

@@ -0,0 +1,25 @@
+# Meeting Template
+
+> Copy this file when creating a new meeting note. Rename it to the date + topic, e.g. `2026-03-31 Sprint Planning.md`
+
+---
+
+**Date:** YYYY-MM-DD
+**Attendees:**
+**Topic:**
+
+---
+
+## Agenda
+1.
+2.
+
+## Discussion Notes
+
+## Decisions Made
+- [ ]
+
+## Action Items
+- [ ] (Owner) Task description — due YYYY-MM-DD
+
+## Next Meeting