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>

GSD-STYLE.md

@@ -483,70 +483,6 @@ How to make tests pass
 
 ---
 
-## Codebase Intelligence
-
-GSD includes an automatic codebase learning system that indexes code and detects patterns.
-
-### Files
-
-| File | Purpose | Updated By |
-|------|---------|------------|
-| `.planning/intel/index.json` | File exports/imports index | PostToolUse hook |
-| `.planning/intel/conventions.json` | Detected naming/directory/suffix patterns | PostToolUse hook |
-| `.planning/intel/summary.md` | Concise context for injection | PostToolUse hook |
-
-### Index Schema
-
-```json
-{
-  "version": 1,
-  "updated": 1234567890,
-  "files": {
-    "/absolute/path/to/file.ts": {
-      "exports": ["functionA", "ClassB", "default"],
-      "imports": ["react", "./utils", "@org/pkg"],
-      "indexed": 1234567890
-    }
-  }
-}
-```
-
-### Convention Detection
-
-**Naming conventions** (requires 5+ exports, 70%+ match rate):
-- camelCase, PascalCase, snake_case, SCREAMING_SNAKE
-- 'default' is skipped (keyword, not naming indicator)
-
-**Directory purposes** (lookup table):
-- components, hooks, utils, lib, services, api, routes, types, models, tests, etc.
-
-**Suffix patterns** (requires 5+ files):
-- .test.*, .spec.*, .service.*, .controller.*, etc.
-
-### Hook Patterns
-
-**PostToolUse hook (intel-index.js):**
-- Triggers on Write/Edit of JS/TS files
-- Incremental update (single file per invocation)
-- Silent failure (never blocks Claude)
-- Regenerates conventions.json and summary.md on every update
-
-**SessionStart hook (intel-session.js):**
-- Triggers on startup/resume
-- Reads index.json and conventions.json
-- Outputs `<codebase-intelligence>` wrapped summary
-- Silent failure if intel files missing
-
-### Commands
-
-**`/gsd:analyze-codebase`** — Bulk scan for brownfield projects:
-- Creates .planning/intel/ directory
-- Scans all JS/TS files (excludes node_modules, dist, build, .git, vendor, coverage)
-- Uses same extraction logic as PostToolUse hook
-- Works standalone (no /gsd:new-project required)
-
----
-
 ## Summary: Core Meta-Patterns
 
 1. **XML for semantic structure, Markdown for content**