chore: sync main fixes into dev

[numnx]

Summary

• Merge origin/main into dev so release-side fixes from the 0.9.2/0.9.3 chain are available on the integration branch.
• Carries Windows release verifier hardening, Playwright launcher hardening, CodeQL/release validation fixes, security/docs updates, local directory route hardening, dashboard chat connection handling, and related tests.

Validation

pnpm run lint
pnpm vitest run tests/backend/infrastructure/git/code-ux-gitignore.test.ts tests/backend/infrastructure/providers/cli/workspace-manager.test.ts tests/backend/server/agent-preset-routes.test.ts tests/backend/server/local-directory-routes.test.ts tests/backend/services/custom-dashboard-validation-service.test.ts tests/backend/services/custom-dashboard-validation-utils.test.ts tests/backend/services/docs-web-catalog-service.test.ts tests/backend/services/embedding-model-catalog.test.ts dashboard/src/v2/lib/__tests__/chat-widget-view-models.test.ts

Risk / Rollback

• Low-risk merge-only sync from main into dev; no manual conflict resolution was needed.
• Roll back by reverting the merge commit if CI exposes an integration regression.