feat: recreate Guardian Pacts tab for Invoker attunement

- Add GuardianPactsTab.tsx with guardian cards organized by floor tier
- Display HP, armor, power stats, boons, unique perk, pact cost per guardian
- Show status: Undefeated / Defeated (pact available) / Pact Signed
- Allow starting pact rituals with defeated guardians
- Show pact ritual progress bar
- Display active pacts and cumulative boon effects
- Show remaining pact slots
- Add tier filter (All / Early / Mid / Late Spire)
- Add to tabs barrel export and page.tsx with lazy loading
- Add DebugName wrapper
- Write 13 tests covering module structure, data integrity, store shape, file size

docs/project-structure.txt

@@ -119,6 +119,8 @@ Mana-Loop/
 │   │   │   │   ├── EquipmentTab.tsx
 │   │   │   │   ├── GolemancyTab.test.ts
 │   │   │   │   ├── GolemancyTab.tsx
+│   │   │   │   ├── GuardianPactsTab.test.ts
+│   │   │   │   ├── GuardianPactsTab.tsx
 │   │   │   │   ├── PrestigeTab.test.ts
 │   │   │   │   ├── PrestigeTab.tsx
 │   │   │   │   ├── SpellsTab.tsx