Eradicate hook files, use pinned beads only (gt-rgd9x)

- Remove hook functions from internal/wisp/io.go (WriteSlungWork, ReadHook, BurnHook, etc.)
- Remove hook types from internal/wisp/types.go (SlungWork, Wisp, etc.)
- Update up.go to query pinned beads instead of reading hook files
- Remove SlungWork field from molecule_status.go
- Remove hook-*.json pattern from .beads/.gitignore
- Delete live hook file /Users/stevey/gt/deacon/.beads/hook-deacon.json

Work is now tracked exclusively via pinned beads (status=pinned, assignee=agent).

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

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

.beads/.gitignore

@@ -31,9 +31,6 @@ beads.right.meta.json
 # bd sync commits to beads-sync, which has its own .gitignore that tracks issues.jsonl
 issues.jsonl
 
-# Hook files (ephemeral, per-agent work attachments)
-hook-*.json
-
 # MR queue (ephemeral, deleted after merge)
 mq/