chore(deps): promote @agentclientprotocol/sdk to a runtime dependency

The smoke script in apps/server/scripts/acp-smoke.ts used the SDK as
devDependency. The upcoming ACP bridge (apps/server/src/api/services/acp/)
needs it at runtime, not just for tooling. Move the entry from
devDependencies to dependencies, alphabetically first under @a*.

Pinned to 0.21.0 — same version the smoke script validated against.
README gains a small Dependencies note pointing at the future bridge
location.

No code changes yet. The bridge wiring lands in subsequent commits.

packages/browseros-agent/apps/server/README.md

@@ -92,6 +92,12 @@ Skills are custom instruction sets that shape agent behavior:
 - **Loader** (`src/skills/loader.ts`) — loads skills from local and remote sources
 - **Remote sync** (`src/skills/remote-sync.ts`) — syncs skills from the BrowserOS cloud
 
+## Dependencies
+
+Notable runtime dependencies worth calling out:
+
+- **`@agentclientprotocol/sdk`** — Agent Client Protocol SDK. Powers the upcoming ACP bridge that drives chat, history, cancellation, and per-session realtime state by spawning `openclaw acp` as a child process and consuming JSON-RPC over stdio. Wiring code lands in `src/api/services/acp/` in subsequent commits.
+
 ## Directory Structure
 
 ```

packages/browseros-agent/apps/server/package.json

@@ -72,6 +72,7 @@
     }
   },
   "dependencies": {
+    "@agentclientprotocol/sdk": "0.21.0",
     "@ai-sdk/amazon-bedrock": "^4.0.62",
     "@ai-sdk/anthropic": "^3.0.46",
     "@ai-sdk/azure": "^3.0.31",
@@ -112,7 +113,6 @@
     "zod-from-json-schema": "^0.1.0"
   },
   "devDependencies": {
-    "@agentclientprotocol/sdk": "0.21.0",
     "@types/bun": "1.3.5",
     "@types/debug": "^4.1.12",
     "@types/node": "^24.3.3",

packages/browseros-agent/bun.lock

@@ -161,6 +161,7 @@
         "browseros-server": "./src/index.ts",
       },
       "dependencies": {
+        "@agentclientprotocol/sdk": "0.21.0",
         "@ai-sdk/amazon-bedrock": "^4.0.62",
         "@ai-sdk/anthropic": "^3.0.46",
         "@ai-sdk/azure": "^3.0.31",
@@ -201,7 +202,6 @@
         "zod-from-json-schema": "^0.1.0",
       },
       "devDependencies": {
-        "@agentclientprotocol/sdk": "0.21.0",
         "@types/bun": "1.3.5",
         "@types/debug": "^4.1.12",
         "@types/node": "^24.3.3",