feat: pre-compaction save + post-compaction memory re-injection

1. Pre-compaction full conversation save:
   - Before compaction, capture ALL conversation messages to supermemory
   - Saves to project, user, and repo scopes with PERSONAL_ENTITY_CONTEXT
   - Ensures no conversation data is lost during compaction
   - Allows 2x maxCaptureChars for compaction saves

2. Post-compaction memory re-injection:
   - After compaction, re-inject supermemory context in the 'Continue' message
   - Recalls user profile, user memories, and repo memories
   - Agent maintains continuity across compaction boundaries
   - Prompt instructs agent to use memory context to resume

3. Summary saves to all scopes:
   - Compaction summary now saved to project + user + repo scopes
   - Uses PERSONAL_ENTITY_CONTEXT for extraction guidance

4. Repo tag support in compaction:
   - createCompactionHook now accepts { user, project, repo } tags