feat(120): alert component unification

Phase 120 - Plan 01:
- Reusable PHP alert component (resources/views/components/alert.php)
  with inline SVG icon per type, optional dismiss button.
- Missing .alert--info SCSS variant added (#eff6ff/#bfdbfe/#1e3a8a) -
  fixes black-on-white alert after Fakturownia test connection.
- Flash::push(type, message) + Flash::all() with BC for set/get;
  legacy key heuristic (error/.save/warning -> typed entries).
- Central flash renderer in 3 layouts (app/auth/public) iterating
  Flash::all() through component (.alerts-stack wrap).
- Vanilla JS alert-dismiss.js with idempotent guard and delegated
  click handler on [data-alert-dismiss].
- 36 views migrated off inline <div class="alert alert--TYPE">;
  .flash--error/success removed from views (orders/show, shipments/prepare).
- SCSS rebuilt: public/assets/css/{app,login}.css.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.paul/ROADMAP.md

@@ -17,6 +17,9 @@ Wystawianie faktur dla klientow z NIP poprzez integracje z Fakturownia (app.fakt
 | 115 | Wystawianie faktury z zamowienia (lokalne + delegacja Fakturownia + NIP lookup MF Biala Lista) | 1/1 | Complete (2026-05-10) |
 | 116 | HostedSMS Integration Settings + Test SMS | 1/1 | Complete (2026-05-12) |
 | 117 | SMSPLANET Integration Settings + Test SMS | 1/1 | Complete (2026-05-12; migration/manual SMS verification pending) |
+| 118 | Fakturownia Single Instance | 1/1 | Applied (2026-05-12; migration/manual Fakturownia verification pending) |
+| 119 | Re-import total_paid Protection | 1/1 | Complete (2026-05-12; phpunit run + manual shoppro smoke pending env) |
+| 120 | Alert Component Unification | 1/1 | Complete (2026-05-12; CSS rebuilt; smoke tests pending operator) |
 
 Planowane kolejne fazy v3.7 (kandydaci, do rozplanowania):
 - Eksport XLSX listy wystawionych faktur (analogicznie do paragonow)
@@ -498,4 +501,4 @@ Archive: `.paul/milestones/v0.1-ROADMAP.md`
 
 ---
 *Roadmap created: 2026-03-12*
-*Last updated: 2026-05-12 - Phase 117 (SMSPLANET Integration Settings + Test SMS) complete with environment verification gaps; v3.7 milestone in progress*
+*Last updated: 2026-05-12 - Phase 118 (Fakturownia Single Instance) applied with environment verification gaps; v3.7 milestone in progress*