revert: remove codebase intelligence system

Rolled back the intel system due to overengineering concerns:
- 1200+ line hook with SQLite graph database
- 21MB sql.js dependency
- Entity generation spawning additional Claude calls
- Complex system with unclear value

Removed:
- /gsd:analyze-codebase command
- /gsd:query-intel command
- gsd-intel-index.js, gsd-intel-session.js, gsd-intel-prune.js hooks
- gsd-entity-generator, gsd-indexer agents
- entity.md template
- sql.js dependency

Preserved:
- Model profiles feature
- Statusline hook
- All other v1.9.x improvements

-3,065 lines removed

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

agents/gsd-executor.md

@@ -52,20 +52,6 @@ git check-ignore -q .planning 2>/dev/null && COMMIT_PLANNING_DOCS=false
 Store `COMMIT_PLANNING_DOCS` for use in git operations.
 </step>
 
-<step name="load_codebase_intelligence">
-Check for codebase intelligence:
-
-```bash
-cat .planning/intel/summary.md 2>/dev/null
-```
-
-If exists:
-- Follow detected naming conventions when writing code
-- Place new files in directories that match their purpose
-- Use established patterns (camelCase, PascalCase, etc.)
-
-This context helps maintain codebase consistency during execution.
-</step>
 
 <step name="load_plan">
 Read the plan file provided in your prompt context.