chore: bootstrap repo with chunks 1 and 2

Establishes the global AI development config repo from scratch:

- Chunk 1: repo skeleton, install.sh, statusline, deploy manifest
- Chunk 2: core instructions (coding/git/testing), CLAUDE.md rewrite
  (always-on + content index two-tier model), docs restructure,
  6 ADRs, ROADMAP.md, .gitkeep placeholders
- Bootstrap skills in .claude/skills/ (to be catalogued and migrated
  to .agents/skills/ in Chunk 3)

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

.gitignore

@@ -0,0 +1,23 @@
+# OS
+.DS_Store
+Thumbs.db
+
+# Editor
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Logs and temp
+*.log
+*.tmp
+/tmp/
+
+# Environment
+.env
+.env.*
+!.env.example
+
+# Node (if tooling is added later)
+node_modules/