chore: bootstrap agent-ready docs, rules and Bun workspace

Adds the approved v1 design spec, UI mockups, AGENTS.md (with CLAUDE.md
and GEMINI.md pointers), architecture/decisions/todo/permissions docs,
agent permission files, and an empty Bun workspaces skeleton.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,25 @@
+node_modules/
+dist/
+*.tsbuildinfo
+coverage/
+
+# local data (SQLite db, attachments, backups, snapshots)
+data/
+*.db
+*.db-shm
+*.db-wal
+
+# secrets
+.env
+.env.*
+!.env.example
+
+# agent scratch
+CLAUDE.local.md
+.superpowers/
+.worktrees/
+.claude/settings.local.json
+
+.DS_Store
+.idea/
+.vscode/