feat: Implement Phase 5 Quest System (100% complete)

Add YAML-driven quest system with context-aware offering:

Core Implementation:
- Quest data models (Quest, QuestObjective, QuestReward, QuestTriggers)
- QuestService for YAML loading and caching
- QuestEligibilityService with level, location, and probability filtering
- LoreService stub (MockLoreService) ready for Phase 6 Weaviate integration

Quest Content:
- 5 example quests across difficulty tiers (2 easy, 2 medium, 1 hard)
- Quest-centric design: quests define their NPC givers
- Location-based probability weights for natural quest offering

AI Integration:
- Quest offering section in npc_dialogue.j2 template
- Response parser extracts [QUEST_OFFER:quest_id] markers
- AI naturally weaves quest offers into NPC conversations

API Endpoints:
- POST /api/v1/quests/accept - Accept quest offer
- POST /api/v1/quests/decline - Decline quest offer
- POST /api/v1/quests/progress - Update objective progress
- POST /api/v1/quests/complete - Complete quest, claim rewards
- POST /api/v1/quests/abandon - Abandon active quest
- GET /api/v1/characters/{id}/quests - List character quests
- GET /api/v1/quests/{quest_id} - Get quest details

Frontend:
- Quest tracker sidebar with HTMX integration
- Quest offer modal for accept/decline flow
- Quest detail modal for viewing progress
- Combat service integration for kill objective tracking

Testing:
- Unit tests for Quest models and serialization
- Integration tests for full quest lifecycle
- Comprehensive test coverage for eligibility service

Documentation:
- Reorganized docs into /docs/phases/ structure
- Added Phase 5-12 planning documents
- Updated ROADMAP.md with new structure

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

api/app/data/quests/hard/dungeon_depths.yaml

@@ -0,0 +1,146 @@
+# Dungeon Depths - Challenging dungeon crawl quest
+quest_id: quest_dungeon_depths
+name: "Secrets of the Old Mines"
+description: |
+  The sealed entrance to Crossville's abandoned mines has been breached.
+  Strange sounds and foul odors emanate from within, and livestock have
+  begun to disappear. The mayor needs someone brave enough to investigate
+  what ancient evil has awakened in the depths.
+difficulty: hard
+
+# NPC Quest Givers
+quest_giver_npc_ids:
+  - npc_mayor_aldric
+quest_giver_name: "Mayor Aldric Thornwood"
+
+# Location context
+location_id: crossville_village
+region_id: crossville
+
+# Offering conditions
+offering_triggers:
+  location_types: ["town", "official"]
+  specific_locations: ["crossville_village", "crossville_town_hall"]
+  min_character_level: 6
+  max_character_level: 15
+  required_quests_completed:
+    - quest_bandit_threat  # Must have proven yourself
+  probability_weights:
+    town: 0.15
+    official: 0.25
+
+# NPC-specific offer dialogue
+npc_offer_dialogues:
+  npc_mayor_aldric:
+    dialogue: |
+      *closes the door and speaks in hushed tones* What I'm about
+      to tell you cannot leave this room. The Old Mines... they were
+      sealed for a reason. My grandfather saw to it fifty years ago.
+      Now something has broken through. I need someone I can trust
+      to go down there and find out what we're dealing with.
+      *pauses* And to ensure it stays buried.
+    conditions:
+      min_relationship: 60
+      required_flags: ["completed_bandit_quest"]
+      forbidden_flags: []
+
+# What NPCs know
+npc_quest_knowledge:
+  npc_mayor_aldric:
+    - "The mines were sealed after a cave-in killed twenty miners"
+    - "His grandfather's journal mentions 'that which must not wake'"
+    - "The recent earthquakes may have disturbed ancient seals"
+    - "He's being blackmailed by someone who knows the truth"
+    - "The Thornwood family has guarded this secret for generations"
+
+# Embedded lore
+lore_context:
+  backstory: |
+    Fifty years ago, miners in Crossville dug too deep and broke into
+    ancient catacombs predating human settlement. What they found
+    drove the survivors mad. The mines were sealed, the entrance
+    buried, and the truth hidden. The Thornwood family has kept
+    this secret ever since, fearing what might happen if the truth
+    emerged.
+  world_connections:
+    - "The catacombs may predate the Five Kingdoms themselves"
+    - "Similar sealed places exist across the realm - ancient evils best forgotten"
+    - "The earthquakes affecting the region all seem centered on these old sites"
+  regional_hints:
+    - "Old-timers speak of the 'quiet years' after the mine closed"
+    - "The Thornwood family rose to prominence around the same time"
+    - "Some say the mayor's nightmares are why he never drinks"
+
+# Narrative hooks
+dialogue_templates:
+  narrative_hooks:
+    - "speaks of family duty and burden"
+    - "reveals more than intended when stressed"
+    - "offers to share grandfather's journal"
+    - "warns of dangers beyond mere monsters"
+  ambient_hints:
+    - "The mayor's hands shake when the mines are mentioned"
+    - "Old maps on his wall show the mine entrance marked with warnings"
+    - "A locked chest in the corner bears the Thornwood seal"
+
+# Objectives
+objectives:
+  - objective_id: enter_mines
+    description: "Enter the Old Mines through the breached seal"
+    objective_type: travel
+    required_progress: 1
+    target_location_id: old_mines_entrance
+
+  - objective_id: explore_depths
+    description: "Explore the mine depths"
+    objective_type: discover
+    required_progress: 3
+    target_location_id: mine_depths
+
+  - objective_id: defeat_guardians
+    description: "Defeat the awakened guardians"
+    objective_type: kill
+    required_progress: 5
+    target_enemy_type: ancient_guardian
+
+  - objective_id: find_crypt
+    description: "Discover the ancient crypt"
+    objective_type: discover
+    required_progress: 1
+    target_location_id: ancient_crypt
+
+  - objective_id: seal_evil
+    description: "Reseal or destroy what lies within"
+    objective_type: interact
+    required_progress: 1
+    target_npc_id: ancient_seal
+
+# Rewards
+rewards:
+  gold: 500
+  experience: 750
+  items:
+    - ancient_medallion
+    - thornwood_journal
+  relationship_bonuses:
+    npc_mayor_aldric: 30
+  unlocks_quests: ["quest_ancient_truth"]
+  reveals_locations: ["old_mines", "ancient_crypt"]
+
+# Completion dialogue
+completion_dialogue:
+  npc_mayor_aldric: |
+    *sinks into his chair* It's done then? The seal holds?
+    *long pause* You've done what my family couldn't for fifty
+    years. You've seen what lies beneath our village. I trust
+    you understand why this must remain secret.
+    *slides a heavy chest across the desk*
+    Your reward. And my eternal gratitude. The Thornwood family
+    owes you a debt we can never fully repay. If you ever need
+    anything... anything at all... my door is always open to you.
+
+tags:
+  - dungeon
+  - combat
+  - story
+  - secret