chore: remove ChromaDB integration

ChromaDB was disabled via feature flag, never used in practice, and added
~15MB of native bindings. Remove all ChromaDB source, hooks, scripts,
templates, config commands, and feature flag references.

- Delete chromadb-adapter.ts, repo-ingestion-skill.ts, storage-config.ts
- Delete 4 ChromaDB hooks (save, startup, code-change, periodic-save)
- Delete 8 ChromaDB scripts and 1 template
- Remove from feature-flags, CLI init, config storage commands
- Remove RepoIngestionSkill from claude-skills.ts
- Remove chromadb from package.json optionalDependencies
- Clean ChromaDB refs from hooks.json, on-task-complete, on-important
- Clean ChromaDB refs from claude-sm-autostart.js

Author: StackMemory Bot (CLI)

.claude/hooks.json

@@ -10,35 +10,13 @@
         "USER_MESSAGE": "{{MESSAGE}}"
       }
     },
-    "on-startup": {
-      "description": "Load context from ChromaDB and setup periodic saves",
-      "command": "node",
-      "args": ["{{PROJECT_ROOT}}/.claude/hooks/on-startup.js"],
-      "async": true,
-      "enabled": true
-    },
-    "on-code-change": {
-      "description": "Save context when code is modified",
-      "triggers": ["edit", "create", "delete"],
-      "command": "node",
-      "args": ["{{PROJECT_ROOT}}/.claude/hooks/on-code-change.js"],
-      "enabled": true
-    },
     "on-task-complete": {
       "description": "Save context and update Linear when tasks complete",
       "triggers": ["task_done", "todo_complete", "completed", "finished"],
       "command": "node",
       "args": ["{{PROJECT_ROOT}}/.claude/hooks/on-task-complete.js"],
       "enabled": true
     },
-    "periodic-save": {
-      "description": "Save context every 1-5 minutes based on activity",
-      "command": "node",
-      "args": ["{{PROJECT_ROOT}}/.claude/hooks/periodic-save.js"],
-      "interval": 60000,
-      "enabled": true,
-      "adaptive": true
-    },
     "linear-update": {
       "description": "Auto-update Linear tasks",
       "triggers": ["STA-", "completed", "implemented", "in progress", "blocked"],
@@ -48,14 +26,6 @@
     }
   },
   "settings": {
-    "chromadb": {
-      "enabled": true,
-      "api_key_env": "CHROMADB_API_KEY",
-      "api_url_env": "CHROMADB_API_URL",
-      "collection": "claude_context",
-      "auto_load_on_startup": true,
-      "save_interval": 900000
-    },
     "linear": {
       "enabled": true,
       "api_key_env": "LINEAR_API_KEY",
@@ -69,4 +39,4 @@
       "rotate_logs": true
     }
   }
-}
+}