feat: add MCP server core, stdio and streamable HTTP transports and serve command

Low-level SDK server built from the catalog plus gitea_api_request, with TOOLSETS/READ_ONLY/DISABLED_TOOLS filters, schema validation without value echo, one audit event per call, static bearer verifier, identity resolver hook, /health, DNS-rebinding protection, rate limiting and fail-closed startup checks.

src/aegis_gitea_mcp/audit.py

@@ -122,8 +122,23 @@ class AuditLogger:
         correlation_id: str | None = None,
         result_status: str = "pending",
         error: str | None = None,
+        *,
+        domain: str | None = None,
+        method: str | None = None,
+        path: str | None = None,
+        identity_login: str | None = None,
+        identity_mode: str | None = None,
+        sudo: str | None = None,
+        outcome: str | None = None,
+        duration_ms: float | None = None,
     ) -> str:
-        """Log an MCP tool invocation."""
+        """Log an MCP tool invocation.
+
+        The keyword-only fields describe a server tool call (tool domain, HTTP
+        method, path template, identity, sudo target, outcome and duration). They
+        are only written when given. Callers must pass argument names, never
+        argument values, in ``params``.
+        """
         payload: dict[str, Any] = {
             "correlation_id": correlation_id or str(uuid.uuid4()),
             "tool_name": tool_name,
@@ -132,6 +147,17 @@ class AuditLogger:
             "params": params or {},
             "result_status": result_status,
         }
+        optional: dict[str, Any] = {
+            "domain": domain,
+            "method": method,
+            "path": path,
+            "identity_login": identity_login,
+            "identity_mode": identity_mode,
+            "sudo": sudo,
+            "outcome": outcome,
+            "duration_ms": duration_ms,
+        }
+        payload.update({key: value for key, value in optional.items() if value is not None})
         if error:
             payload["error"] = error
         return self._append_entry("tool_invocation", payload)