[dviejokfs]

Summary

Fixes two user-reported bugs in one branch, plus tightens backend project-creation consistency and error mapping.

1. Deployment logs WebSocket dies on redeploy

web/src/components/deployments/DeploymentStages.tsx

The log stream gave up the moment it received any normal (1000) closure — exactly what happens when a redeploy churns the underlying log source — leaving the user staring at a frozen log pane. It also wiped state on every reconnect, so the partial logs they had were lost too.

• Always reconnect until unmount; exponential backoff capped at 10s
• Preserve prior log state instead of clearing it
• Dedupe by absolute file line so the backend's last-1000-lines replay after reconnect doesn't show up twice

2. Single click → 15 duplicate projects

web/src/components/project/{ProjectConfigurator,ManualProjectConfigurator}.tsx

Submit was disabled via React state (isSubmitting), but state updates aren't synchronous — fast double-clicks slipped multiple submissions through before the disabled prop landed. Adds a useRef synchronous re-entry guard at the top of handleSubmit in both configurators.

3. Backend project-create consistency

When create_project failed any step after the project row was inserted (default env, env vars, storage links), the project row was left dangling. The handler returned 500 and the user ended up with a half-initialized project visible in their list. The real failure was buried inside ProjectError::Other(format!(...)) so the HTTP status was always 500 even when the cause was a 4xx.

• Manual rollback via CASCADE delete: post-insert work moved to finalize_project_creation, on error Entity::delete_by_id on the project row cascades to environments, env vars, links. No long-running transaction → no cross-service table locks.
• New typed ProjectError variants: SlugConflict, EnvironmentCreationFailed, EnvVarCreationFailed, StorageLinkFailed — all with structured fields per CLAUDE.md error rules.
• SlugAlreadyExists now correctly maps to 409 (was 400). Concurrent slug races now surface as SlugConflict → 409 instead of a generic 500.
• is_unique_violation helper classifies via SQLSTATE 23505 + RecordNotInserted + textual fallbacks.

Test plan

Backend (crates/temps-projects, 41 passed including 5 new):

• test_is_unique_violation_detects_record_not_inserted — pure unit, classifier coverage
• test_create_project_succeeds_and_creates_default_environment — happy path + auto-env
• test_create_project_with_duplicate_name_gets_suffixed_slug — duplicate name → name-<6char>
• test_create_project_slug_conflict_returns_typed_error — real PG unique-violation classified, Problem is HTTP 409
• test_create_project_rolls_back_on_invalid_storage_service — validation path leaves zero phantom projects

Frontend:

• Manually verify logs page reconnects after triggering a redeploy on a project with a long-running deploy
• Manually rage-click "Create Project" — only one project should be created (check /projects list)
• Slow network throttling: confirm second submission attempt is blocked synchronously

Verification commands:

```bash
cargo check --lib # 0 errors
cargo test --lib -p temps-projects # 41 passed
cd web && bunx tsc --noEmit # no new TS errors vs main
```