add 11 new sub-agent types, fix model routing, add models.json

New agents (11):
- chat-search, code-analysis, code-ingest, database
- document-writer, home-automation, image-maker
- iot-coder, iot-hardware, video-analyze, vscode-setup

Fixes:
- Remove broken :deepseek suffix from coder-basic, coder-pro,
  devops-basic, devops-pro (caused silent fallback to parent model)
- Add models.json with openRouterRouting for DeepSeek, Qwen,
  MiniMax, Moonshot AI provider cache targeting

Additions:
- headroom-bridge extension (compress_for_agent tool)
- models.json with provider routing config

Cleanup:
- Remove old pi-subagents extension (replaced by @tintinweb/pi-subagents)

extensions/package-lock.json

@@ -0,0 +1,45 @@
+{
+  "name": "extensions",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "extensions",
+      "version": "1.0.0",
+      "license": "ISC",
+      "dependencies": {
+        "headroom-ai": "^0.22.4"
+      }
+    },
+    "node_modules/headroom-ai": {
+      "version": "0.22.4",
+      "resolved": "https://registry.npmjs.org/headroom-ai/-/headroom-ai-0.22.4.tgz",
+      "integrity": "sha512-9a0rgB/jsWe8gs/ggyUwe6E8DYwKAuBvlUml2ApwlUjb5EfJ611X6X+WG0SiXw3nO6sdyV1/+Ah5uw9P7ecnjw==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=18.0.0"
+      },
+      "peerDependencies": {
+        "@ai-sdk/provider": ">=1.0.0",
+        "@anthropic-ai/sdk": ">=0.30.0",
+        "ai": ">=6.0.0",
+        "openai": ">=4.0.0"
+      },
+      "peerDependenciesMeta": {
+        "@ai-sdk/provider": {
+          "optional": true
+        },
+        "@anthropic-ai/sdk": {
+          "optional": true
+        },
+        "ai": {
+          "optional": true
+        },
+        "openai": {
+          "optional": true
+        }
+      }
+    }
+  }
+}