feat(v3.12.0): media pipeline, AI image generation, capability probe, companion v2.9.0

Three-month batch sync from internal repo (~80 commits) covering Tracks F.5a, F.7e, F.8, F.17, F.18, F.X.

WordPress media pipeline
- Pillow-based optimization, AI image generation (OpenAI / Stability / Replicate / Google Nano Banana / OpenRouter), chunked + resumable uploads, bulk delete/reassign, idempotent retries.

Capability discovery (F.7e)
- Per-site credential probe + adapters for WordPress / WooCommerce / Gitea, tier-fit unions granted ∪ roles, capability badge UI with HTMX partial re-check, install hint in every companion-unreachable error.

Companion plugin overhaul
- Renamed wordpress-plugin/airano-mcp-seo-bridge → wordpress-plugin/airano-mcp-bridge.
- Eight new endpoints: /capabilities, /bulk-meta, /export, /cache-purge, /transient-flush, /site-health, /audit-hook, /upload-and-attach.
- wp.org Plugin Check pass: i18n, WP_Filesystem, scheme allowlist on audit-hook URL.

Other
- Gitea ergonomics (F.17): batch files, tree, search, compare, releases, fork.
- Opportunistic bcrypt upgrade for legacy SHA-256 admin keys (F.8).
- n8n refactor: structured errors, capability probe, missing tools backfilled.
- Idempotency-Key dedup for AI media upload retries; WP client fast-fails on unreachable sites.

Docs
- README + CLAUDE.md drop the fixed "633 tools" claim. The total grows with each release; per-plugin approximations + dashboard-surfaced counts replace it.
- Tools/Tests badges removed in favour of "Plugins: 10".

Deployment
- PyPI mirror chain, optional BUILD_HTTP_PROXY, Alpine→Yandex apk mirror, Debian-slim Plan-B Dockerfile, mirror.gcr.io variant.

CI
- Black + Ruff clean on Python 3.12; pytest tests/ green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/n8n/handlers/credentials.py

@@ -1,9 +1,15 @@
-"""Credentials Handler - manages n8n credentials"""
+"""Credentials Handler - manages n8n credentials."""
 
 import json
 from typing import Any
 
-from plugins.n8n.client import N8nClient
+from plugins.n8n.client import N8nApiError, N8nClient
+
+
+def _error_json(exc: Exception) -> str:
+    if isinstance(exc, N8nApiError):
+        return json.dumps({"success": False, **exc.to_dict()}, indent=2)
+    return json.dumps({"success": False, "error": str(exc)}, indent=2)
 
 
 def get_tool_specifications() -> list[dict[str, Any]]:
@@ -107,7 +113,7 @@ async def get_credential(client: N8nClient, credential_id: str) -> str:
         }
         return json.dumps(result, indent=2)
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def create_credential(client: N8nClient, name: str, type: str, data: dict[str, Any]) -> str:
@@ -126,7 +132,7 @@ async def create_credential(client: N8nClient, name: str, type: str, data: dict[
         }
         return json.dumps(result, indent=2)
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def delete_credential(client: N8nClient, credential_id: str) -> str:
@@ -137,7 +143,7 @@ async def delete_credential(client: N8nClient, credential_id: str) -> str:
             {"success": True, "message": f"Credential {credential_id} deleted"}, indent=2
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def get_credential_schema(client: N8nClient, credential_type: str) -> str:
@@ -148,7 +154,7 @@ async def get_credential_schema(client: N8nClient, credential_type: str) -> str:
             {"success": True, "credential_type": credential_type, "schema": schema}, indent=2
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def transfer_credential(
@@ -165,4 +171,4 @@ async def transfer_credential(
             indent=2,
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)