fix: enforce fix(deps) semantic commit prefix in renovate config

Without an explicit semanticCommitType override, Renovate defaults
major-version and github-actions bumps to a `chore:` commit prefix,
which violates this org's fix:/feat:-only commit convention. Adds the
same semanticCommits block already used by mcp-core and web-core.

Author: n24q02m

renovate.json

@@ -131,5 +131,16 @@
       ],
       "enabled": false
     }
-  ]
+  ],
+  "semanticCommits": "enabled",
+  "commitMessagePrefix": "fix(deps):",
+  "commitMessageAction": "update",
+  "commitMessageTopic": "{{depName}}",
+  "semanticCommitType": "fix",
+  "semanticCommitScope": "deps",
+  "golang": {
+    "postUpdateOptions": [
+      "gomodTidy"
+    ]
+  }
 }