Send the catalog User-Agent on calls from installed connectors - #1539

Summary

sevdesk asks technology partners to send a User-Agent on every API call (requirement #2 of its partner programme). Our sevdesk adapter sent none. Adding the header to the adapter alone is not enough: the header is copied onto a connector at install, and catalog sync never updates stored headers (CatalogResyncService "never touches auth/envVars/headers"), so connectors installed earlier would keep sending none.

Changes

• de/sevdesk.json: "headers": {"User-Agent": "AnythingMCP ([email protected])"} (same value as br/tiendanube.json).
• connectors/catalog-user-agent.util.ts: withCatalogUserAgent(headers, connectorConfig). For a catalog connector (config.adapterSlug) with no User-Agent, add the adapter's User-Agent. Rules:
  • only a static value (no {{VAR}}) is used;
  • a User-Agent stored on the connector always wins, whatever its case;
  • hand-made connectors are unchanged;
  • no database write.
• Applied where request headers are built: tool calls (dynamic-mcp-tools.ts), ConnectorsService tool execution and the connection test.
• Production check before merging: of all connectors whose adapter has a static User-Agent, the only ones without it today are the 15 sevdesk connectors. So in practice this changes sevdesk calls only.
• Cloud and self-hosted behave the same: the catalog ships with the image.

Type

• Bug fix

Testing

• Added/updated unit tests

In packages/backend:

• npx jest src/connectors/catalog-user-agent.util.spec.ts: 6 passed. The tests cover:
  • the adapter declares the header;
  • it is added when missing;
  • a stored one wins;
  • hand-made, unknown and no-header adapters are unchanged;
  • a templated value is ignored;
  • an on-the-wire test with a local HTTP server receives user-agent: AnythingMCP ([email protected]) on a sevdesk call.
• npx eslint on the 4 changed TS files: clean.
• node scripts/validate-adapters.mjs --warn: no sevdesk warnings. node scripts/regenerate-catalog.mjs: no catalog diff.
• Locally, tsc and the dynamic-mcp-tools* / connectors.service* suites fail to compile because the shared local node_modules lacks @types/picomatch and other modules. That is a baseline of this machine, unrelated to this change, and the same on main. CI runs the full suites.

Checklist

• My code follows the existing code style
• I have tested my changes locally
• This PR has a descriptive title

Related Issues

None (sevdesk technology partner requirement).