fix: redact stored webhook authorization headers and other secret fields by key name (SEC-02)

src/aegis_gitea_mcp/gitea/executor.py

@@ -13,6 +13,9 @@ Security properties (all covered by tests):
 * the identity token and ``Identity.redact``, the configured Gitea token, the MCP bearer token, the
   OAuth client secret, ``extra_secrets`` and secret values submitted in a
   request body are replaced with ``[REDACTED]`` in every result, always;
+* secret-bearing response fields (:data:`~.encoding.SENSITIVE_RESPONSE_KEYS`, for example a
+  webhook's stored ``authorization_header``) are redacted by key name in every result except
+  those of :data:`CREDENTIAL_ISSUING_OPERATIONS`, whatever ``SECRET_DETECTION_MODE`` says;
 * secret-pattern masking/blocking follows ``SECRET_DETECTION_MODE``, except for
   :data:`CREDENTIAL_ISSUING_OPERATIONS` whose purpose is to return a freshly
   minted credential (exact redaction still applies there);
@@ -38,6 +41,7 @@ from aegis_gitea_mcp.config import Settings
 from aegis_gitea_mcp.errors import kind_for_status, sanitize_message
 from aegis_gitea_mcp.gitea.encoding import (
     RAW_METHODS,
+    SENSITIVE_RESPONSE_KEYS,
     ArgumentError,
     PayloadTooLargeError,
     RequestBody,
@@ -50,7 +54,12 @@ from aegis_gitea_mcp.gitea.encoding import (
     validate_sudo,
 )
 from aegis_gitea_mcp.gitea.pagination import build_pagination
-from aegis_gitea_mcp.gitea.redaction import normalize_secrets, redact_exact, redact_text
+from aegis_gitea_mcp.gitea.redaction import (
+    normalize_secrets,
+    redact_exact,
+    redact_fields,
+    redact_text,
+)
 from aegis_gitea_mcp.identity import Identity
 from aegis_gitea_mcp.security import sanitize_data
 
@@ -613,6 +622,10 @@ class GiteaExecutor:
         """Redact, mask or block, and bound the payload size."""
         secrets = self._secrets(identity, call)
         payload = redact_exact(payload, secrets)
+        if not exempt and "data" in payload:
+            # Stored secrets (webhook authorization headers, ...) by field name: pattern
+            # masking cannot recognise them and SECRET_DETECTION_MODE may be off.
+            payload = {**payload, "data": redact_fields(payload["data"], SENSITIVE_RESPONSE_KEYS)}
         mode = self._settings.secret_detection_mode
         if mode != "off" and not exempt:
             if mode == "block":