chore: narrow no_vector_db supported scope

[evan-onyx]

Description

disallow deployments running with no_vector_db from being multi-tenant or using craft

How Has This Been Tested?

unit tests

Additional Options

• [Optional] Please cherry-pick this PR to the latest release version.
• [Optional] Override Linear Check

---

Summary by cubic

Adds startup validation to block DISABLE_VECTOR_DB when combined with MULTI_TENANT or ENABLE_CRAFT. This fails fast and limits no-vector-DB mode to single-tenant, no-Craft deployments.

• Migration
  • If DISABLE_VECTOR_DB=true, set MULTI_TENANT=false.
  • Set ENABLE_CRAFT=false when disabling the vector DB.

^{Written for commit 033aeee. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

[greptile-apps]

Greptile Summary

Added startup validation to prevent DISABLE_VECTOR_DB from being combined with MULTI_TENANT or ENABLE_CRAFT settings. The validation runs during app startup and provides clear error messages explaining why these combinations are incompatible.

• Prevents multi-tenant deployments with no vector DB (requires per-tenant indexing)
• Prevents Craft mode with no vector DB (requires background workers)
• Includes comprehensive unit tests covering all scenarios
• Minor style inconsistency: lazy import of ENABLE_CRAFT inside function while MULTI_TENANT is imported at module level

Confidence Score: 4/5

• This PR is safe to merge with minimal risk
• The validation logic is straightforward and well-tested. The only issue is a minor style inconsistency in import placement that doesn't affect functionality. Clear error messages and comprehensive test coverage reduce risk.
• No files require special attention - the implementation is clean with good test coverage

Important Files Changed

Filename	Overview
backend/onyx/main.py	Added validation to prevent DISABLE_VECTOR_DB from being used with MULTI_TENANT or ENABLE_CRAFT settings, with clear error messages
backend/tests/unit/onyx/test_startup_validation.py	Comprehensive unit tests covering all validation scenarios including edge cases and error message verification

_{Last reviewed commit: 033aeee}

[greptile-apps]

_{2 files reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

[greptile-apps]

Import ENABLE_CRAFT at module level with other imports for consistency, since MULTI_TENANT is already imported at the top (line 158)

Context Used: Context from dashboard - contributing_guides/best_practices.md (source)

_{Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!}

[github-actions]

🖼️ Visual Regression Report

Project	Changed	Added	Removed	Unchanged	Report
admin	1	0	0	108	View Report
exclusive	0	0	0	8	✅ No changes