fix(GRO-2299): redact googleMapsApiKey from PATCH /api/admin/settings response

The PATCH handler returned the full businessSettings row via .returning(),
echoing the encrypted googleMapsApiKey ciphertext back to the caller. Wrap the
return in the existing redactSettings() helper (after a !updated guard) so
redaction is applied symmetrically with the GET projection (GRO-2294).

- src/routes/settings.ts: guard + redactSettings(updated) on PATCH return
- src/__tests__/settings.test.ts: assert PATCH omits googleMapsApiKey
  (existing-row and auto-create-then-update branches)
- UAT_PLAYBOOK.md §13 TC-API-13.2: assert PATCH response omits the secret

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.mcp.json

@@ -0,0 +1,11 @@
+{
+  "mcpServers": {
+    "gitea": {
+      "type": "http",
+      "url": "https://git-mcp.farh.net/mcp",
+      "headers": {
+        "Authorization": "Bearer ${GITEA_TOKEN}"
+      }
+    }
+  }
+}