Add MCC wrappers and guards for build and publish

.codex/hooks.json

@@ -0,0 +1,16 @@
+{
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "/usr/bin/python3 \"$(git rev-parse --show-toplevel)/.codex/hooks/pre_tool_use_mcc_build_guard.py\"",
+            "statusMessage": "Checking MCC build command policy"
+          }
+        ]
+      }
+    ]
+  }
+}

.codex/hooks/pre_tool_use_mcc_build_guard.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+import json
+import re
+import sys
+
+
+RAW_DOTNET_BUILD_RE = re.compile(r"(^|[\s;&|()])dotnet\s+build(\s|$)")
+ABSOLUTE_DOTNET_BUILD_RE = re.compile(r"(^|[\s;&|()])/\S*dotnet\s+build(\s|$)")
+RAW_DOTNET_PUBLISH_RE = re.compile(r"(^|[\s;&|()])dotnet\s+publish(\s|$)")
+ABSOLUTE_DOTNET_PUBLISH_RE = re.compile(r"(^|[\s;&|()])/\S*dotnet\s+publish(\s|$)")
+
+
+def main() -> int:
+    try:
+        payload = json.load(sys.stdin)
+    except json.JSONDecodeError:
+        return 0
+
+    command = payload.get("tool_input", {}).get("command", "")
+    if not isinstance(command, str) or not command:
+        return 0
+
+    if ABSOLUTE_DOTNET_BUILD_RE.search(command) or ABSOLUTE_DOTNET_PUBLISH_RE.search(command):
+        return 0
+
+    if RAW_DOTNET_BUILD_RE.search(command):
+        response = {
+            "hookSpecificOutput": {
+                "hookEventName": "PreToolUse",
+                "permissionDecision": "deny",
+                "permissionDecisionReason": (
+                    "Raw 'dotnet build' is blocked in this repository. "
+                    "Use 'source tools/mcc-env.sh && mcc-build' instead so MCC temp-build routing stays active. "
+                    "If you intentionally need the raw .NET CLI, call it by absolute path such as '/usr/bin/dotnet build ...' to bypass this guard."
+                ),
+            },
+            "systemMessage": (
+                "Blocked raw 'dotnet build'. Use 'source tools/mcc-env.sh && mcc-build'. "
+                "If you intentionally need raw .NET CLI behavior, call '/usr/bin/dotnet build ...' explicitly."
+            ),
+        }
+        json.dump(response, sys.stdout)
+        sys.stdout.write("\n")
+    elif RAW_DOTNET_PUBLISH_RE.search(command):
+        response = {
+            "hookSpecificOutput": {
+                "hookEventName": "PreToolUse",
+                "permissionDecision": "deny",
+                "permissionDecisionReason": (
+                    "Raw 'dotnet publish' is blocked in this repository. "
+                    "Use 'source tools/mcc-env.sh && mcc-publish --rid <RID>' instead so MCC publish defaults stay aligned with the repo workflow. "
+                    "If you intentionally need the raw .NET CLI, call it by absolute path such as '/usr/bin/dotnet publish ...' to bypass this guard."
+                ),
+            },
+            "systemMessage": (
+                "Blocked raw 'dotnet publish'. Use 'source tools/mcc-env.sh && mcc-publish --rid <RID>'. "
+                "If you intentionally need raw .NET CLI behavior, call '/usr/bin/dotnet publish ...' explicitly."
+            ),
+        }
+        json.dump(response, sys.stdout)
+        sys.stdout.write("\n")
+
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())