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/variables.py

@@ -1,9 +1,15 @@
-"""Variables Handler - manages n8n environment variables"""
+"""Variables Handler - manages n8n environment variables."""
 
 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]]:
@@ -106,7 +112,7 @@ async def list_variables(client: N8nClient, limit: int = 100, cursor: str | None
         }
         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 get_variable(client: N8nClient, key: str) -> str:
@@ -120,7 +126,7 @@ async def get_variable(client: N8nClient, key: str) -> str:
             indent=2,
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def create_variable(client: N8nClient, key: str, value: str) -> str:
@@ -135,7 +141,7 @@ async def create_variable(client: N8nClient, key: str, value: str) -> str:
             indent=2,
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def update_variable(client: N8nClient, key: str, value: str) -> str:
@@ -150,7 +156,7 @@ async def update_variable(client: N8nClient, key: str, value: str) -> str:
             indent=2,
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def delete_variable(client: N8nClient, key: str) -> str:
@@ -158,7 +164,7 @@ async def delete_variable(client: N8nClient, key: str) -> str:
         await client.delete_variable(key)
         return json.dumps({"success": True, "message": f"Variable '{key}' deleted"}, indent=2)
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)
 
 
 async def set_variables(client: N8nClient, variables: dict[str, str]) -> str:
@@ -190,4 +196,4 @@ async def set_variables(client: N8nClient, variables: dict[str, str]) -> str:
             indent=2,
         )
     except Exception as e:
-        return json.dumps({"success": False, "error": str(e)}, indent=2)
+        return _error_json(e)