feat(api): implement combat loot integration with hybrid static/procedural system

Add CombatLootService that orchestrates loot generation from combat,
supporting both static item drops (consumables, materials) and procedural
equipment generation (weapons, armor with affixes).

Key changes:
- Extend LootEntry model with LootType enum (STATIC/PROCEDURAL)
- Create StaticItemLoader service for consumables/materials from YAML
- Create CombatLootService with full rarity formula incorporating:
  - Party average level
  - Enemy difficulty tier (EASY: +0%, MEDIUM: +5%, HARD: +15%, BOSS: +30%)
  - Character luck stat
  - Per-entry rarity bonus
- Integrate with CombatService._calculate_rewards() for automatic loot gen
- Add boss guaranteed drops via generate_boss_loot()

New enemy variants (goblin family proof-of-concept):
- goblin_scout (Easy) - static drops only
- goblin_warrior (Medium) - static + procedural weapon drops
- goblin_chieftain (Hard) - static + procedural weapon/armor drops

Static items added:
- consumables.yaml: health/mana potions, elixirs, food
- materials.yaml: trophy items, crafting materials

Tests: 59 new tests across 3 test files (all passing)

docs/PHASE4_COMBAT_IMPLEMENTATION.md

@@ -1757,37 +1757,69 @@ base_damage = attacker_stats.spell_power + ability_base_power  # Magical
 
 ---
 
-### Future Work: Combat Loot Integration
+### Task 2.7: Combat Loot Integration ✅ COMPLETE
 
-**Status:** Planned for future phase
+**Status:** Complete
 
-The ItemGenerator is ready for integration with combat loot drops. Future implementation will:
+Integrated the ItemGenerator with combat loot drops via a hybrid loot system supporting both static and procedural drops.
 
-**1. Update Enemy Loot Tables** - Add procedural generation options:
+**Implementation Summary:**
 
+**1. Extended LootEntry Model** (`app/models/enemy.py`):
 ```yaml
-# Example enhanced enemy loot entry
+# New hybrid loot table format
 loot_table:
-  - type: "static"
+  - loot_type: "static"
     item_id: "health_potion_small"
     drop_chance: 0.5
-  - type: "generated"
+  - loot_type: "procedural"
     item_type: "weapon"
-    rarity_range: ["rare", "epic"]
+    rarity_bonus: 0.10
     drop_chance: 0.1
 ```
 
-**2. Integrate with CombatService._calculate_rewards()** - Use ItemGenerator for loot rolls
+**2. Created CombatLootService** (`app/services/combat_loot_service.py`):
+- Orchestrates loot generation from combat encounters
+- Combines StaticItemLoader (consumables) + ItemGenerator (equipment)
+- Full rarity formula: `effective_luck = base_luck + (entry_bonus + difficulty_bonus + loot_bonus) * 20`
 
-**3. Boss Guaranteed Drops** - Higher-tier enemies guarantee better rarity
+**3. Created StaticItemLoader** (`app/services/static_item_loader.py`):
+- Loads predefined items from `app/data/static_items/` YAML files
+- Supports consumables, materials, and quest items
 
-**4. Luck Stat Integration** - Player luck affects all loot rolls
+**4. Integrated with CombatService._calculate_rewards()**:
+- Builds `LootContext` from encounter (party level, luck, difficulty)
+- Calls `CombatLootService.generate_loot_from_enemy()` for each defeated enemy
+- Boss enemies get guaranteed equipment drops via `generate_boss_loot()`
 
-**Implementation Notes:**
-- Current enemy loot tables use `item_id` references (static items only)
-- ItemGenerator provides `generate_loot_drop(character_level, luck_stat)` method
-- Generated items must be stored as full objects (not IDs) in character inventory
-- Consider adding `LootService` wrapper for consistent loot generation across all sources
+**5. Difficulty Rarity Bonuses:**
+- EASY: +0% | MEDIUM: +5% | HARD: +15% | BOSS: +30%
+
+**6. Enemy Variants Created** (proof-of-concept):
+- `goblin_scout.yaml` (Easy) - static drops only
+- `goblin_warrior.yaml` (Medium) - static + 8% procedural weapon
+- `goblin_chieftain.yaml` (Hard) - static + 25% weapon, 15% armor
+
+**Files Created:**
+- `app/services/combat_loot_service.py`
+- `app/services/static_item_loader.py`
+- `app/data/static_items/consumables.yaml`
+- `app/data/static_items/materials.yaml`
+- `app/data/enemies/goblin_scout.yaml`
+- `app/data/enemies/goblin_warrior.yaml`
+- `app/data/enemies/goblin_chieftain.yaml`
+- `tests/test_loot_entry.py` (16 tests)
+- `tests/test_static_item_loader.py` (19 tests)
+- `tests/test_combat_loot_service.py` (24 tests)
+
+**Checklist:**
+- [x] LootType enum and extended LootEntry (backward compatible)
+- [x] StaticItemLoader service for consumables/materials
+- [x] CombatLootService with full rarity formula
+- [x] CombatService integration with `_build_loot_context()`
+- [x] Static items YAML files (consumables, materials)
+- [x] Goblin variant YAML files (scout, warrior, chieftain)
+- [x] Unit tests (59 new tests passing)
 
 ---