refactor: inject tenant id in tenant-only console handlers

[Tianlel]

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Summary

Part of #36585.

This PR applies the existing with_current_tenant_id decorator to console handlers in tenant-id-only controller files.

It updates these files:

• api/controllers/console/app/generator.py
• api/controllers/console/app/mcp_server.py
• api/controllers/console/workspace/models.py

These handlers now receive current_tenant_id or tenant_id directly instead of unpacking current_account_with_tenant() and discarding the account.

Test updates are included for generator, MCP server, and workspace model handlers.

Screenshots

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Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran make lint && make type-check (backend) and cd web && pnpm exec vp staged (frontend) to appease the lint gods

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	45.79%	45.81%	+0.02%
Strict coverage	45.31%	45.33%	+0.02%
Typed symbols	24,531	24,552	+21
Untyped symbols	29,352	29,352	0
Modules	2740	2740	0