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

.obsidian/app.json

@@ -0,0 +1,12 @@
+{
+  "useMarkdownLinks": true,
+  "newFileLocation": "folder",
+  "newFileFolderPath": "_notes/08 - Meetings & Notes",
+  "attachmentFolderPath": "_notes/assets",
+  "defaultViewMode": "source",
+  "foldHeading": false,
+  "showLineNumber": true,
+  "readableLineLength": true,
+  "strictLineBreaks": false,
+  "showFrontmatter": false
+}

.obsidian/community-plugins.json

@@ -0,0 +1,7 @@
+[
+  "dataview",
+  "obsidian-kanban",
+  "templater-obsidian",
+  "calendar",
+  "obsidian-tasks-plugin"
+]

.obsidian/core-plugins.json

@@ -0,0 +1,23 @@
+{
+  "file-explorer": true,
+  "global-search": true,
+  "switcher": true,
+  "graph": true,
+  "backlink": true,
+  "canvas": true,
+  "outgoing-link": true,
+  "tag-pane": true,
+  "properties": true,
+  "note-composer": true,
+  "command-palette": true,
+  "editor-status": true,
+  "starred": true,
+  "markdown-importer": false,
+  "zk-prefixer": false,
+  "random-note": false,
+  "outline": true,
+  "word-count": true,
+  "file-recovery": true,
+  "publish": false,
+  "sync": false
+}