fix(hooks): restore with UserPromptSubmit prompt hook

UserPromptSubmit fires before each user prompt. Returns ok:true (silent)
if skills are already applied, ok:false with reason only when not applied.
No more Stop hook error noise.

hooks/hooks.json

@@ -0,0 +1,10 @@
+{
+  "hooks": {
+    "UserPromptSubmit": [{
+      "hooks": [{
+        "type": "prompt",
+        "prompt": "Hub-guide best-practice skills are active for this session. MANDATORY: engineering-principles, clean-code, clean-architecture, testing, error-handling, security, git-workflow, api-design. Never assume or guess — always find evidence in codebase or docs. If these skills are already being applied, respond: {\"ok\": true}. If NOT being applied, respond: {\"ok\": false, \"reason\": \"[hub-guide] Apply MANDATORY skills to this session.\"}"
+      }]
+    }]
+  }
+}