Update documentation to reflect current implementation and features

- Expand README.md with complete feature list (quests, vendors, combat, spells, inventory, etc.)
- Update Controls section with comprehensive keybindings organized by category
- Rewrite docs/quickstart.md from "TODO" state to reflect all working features
- Enhance docs/architecture.md with detailed system descriptions and current capabilities
- Add CHANGELOG.md documenting 50+ recent commits grouped by feature area
- Add FEATURES.md with 100+ documented features across 8 major categories
- Update technical details with architecture, networking, and asset loading info

docs/architecture.md

@@ -135,93 +135,197 @@ Wowee follows a modular architecture with clear separation of concerns:
 ### 5. Game Logic (`src/game/`)
 
 **GameHandler** - World server protocol
-- Connects to port 8129
-- Packet handlers for all opcodes
-- Session management
+- Connects to port 8085 (configurable)
+- Packet handlers for 100+ opcodes
+- Session management with RC4 encryption
+- Character enumeration and login flow
 
 **World** - Game world state
-- Map loading
-- Entity management
-- Terrain streaming
+- Map loading with async terrain streaming
+- Entity management (players, NPCs, creatures)
+- Zone management and exploration
+- Time-of-day synchronization
 
 **Player** - Player character
-- Position and movement
-- Stats and inventory
-- Action queue
+- Position and movement (WASD + spline movement)
+- Stats tracking (health, mana, XP, level)
+- Equipment and inventory (23 + 16 slots)
+- Action queue and spell casting
+- Death and resurrection handling
+
+**Character** - Character data
+- Race, class, gender, appearance
+- Creation and customization
+- 3D model preview
+- Persistence (online and offline)
 
 **Entity** - Game entities
-- NPCs and creatures
-- Base entity functionality
-- GUID management
+- NPCs and creatures with display info
+- Animation state (idle, combat, walk, run)
+- GUID management (player, creature, item, gameobject)
+- Targeting and selection
+
+**Inventory** - Item management
+- Equipment slots (head, shoulders, chest, etc.)
+- Backpack storage (16 slots)
+- Item metadata (icons, stats, durability)
+- Drag-drop system
+- Auto-equip and unequip
+
+**NPCManager** - NPC interactions
+- Gossip system
+- Quest givers with markers (! and ?)
+- Vendors (buy/sell)
+- Trainers (placeholder)
+- Combat animations
+
+**ZoneManager** - Zone and area tracking
+- Map exploration
+- Area discovery
+- Zone change detection
 
 **Opcodes** - Protocol definitions
-- Client→Server opcodes (CMSG_*)
-- Server→Client opcodes (SMSG_*)
-- WoW 3.3.5a specific
+- 100+ Client→Server opcodes (CMSG_*)
+- 100+ Server→Client opcodes (SMSG_*)
+- WoW 3.3.5a (build 12340) specific
 
 ### 6. Asset Pipeline (`src/pipeline/`)
 
 **MPQManager** - Archive management
 - Loads .mpq files (via StormLib)
-- File lookup
-- Data extraction
+- Priority-based file lookup (patch files override base files)
+- Data extraction with caching
+- Locale support (enUS, enGB, etc.)
 
 **BLPLoader** - Texture parser
 - BLP format (Blizzard texture format)
-- DXT compression support
-- Mipmap extraction
+- DXT1/3/5 compression support
+- Mipmap extraction and generation
+- OpenGL texture object creation
 
 **M2Loader** - Model parser
-- Character/creature models
-- Skeletal animation data
-- Bone hierarchies
-- Animation sequences
+- Character/creature models with materials
+- Skeletal animation data (256 bones max)
+- Bone hierarchies and transforms
+- Animation sequences (idle, walk, run, attack, etc.)
+- Particle emitters (WotLK FBlock format)
+- Attachment points (weapons, mounts, etc.)
+- Geoset support (hide/show body parts)
+- Multiple texture units and render batches
 
 **WMOLoader** - World object parser
 - Buildings and structures
-- Static geometry
-- Portal system
-- Doodad placement
+- Multi-material batches
+- Portal system (visibility culling)
+- Doodad placement (decorations)
+- Group-based rendering
+- Liquid data (indoor water)
 
 **ADTLoader** - Terrain parser
-- 16x16 chunks per map
-- Height map data
-- Texture layers (up to 4)
-- Liquid data (water/lava)
-- Object placement
+- 64x64 tiles per map (map_XX_YY.adt)
+- 16x16 chunks per tile (MCNK)
+- Height map data (9x9 outer + 8x8 inner vertices)
+- Texture layers (up to 4 per chunk with alpha blending)
+- Liquid data (water/lava/slime with height and flags)
+- Object placement (M2 and WMO references)
+- Terrain holes
+- Async loading to prevent frame stalls
 
 **DBCLoader** - Database parser
-- Game data tables
-- Creature/spell/item definitions
-- Map and area information
+- 20+ DBC files loaded (Spell, Item, Creature, SkillLine, Faction, etc.)
+- Type-safe record access
+- String block parsing
+- Memory-efficient caching
+- Used for:
+  - Spell icons and tooltips (Spell.dbc, SpellIcon.dbc)
+  - Item data (Item.dbc, ItemDisplayInfo.dbc)
+  - Creature display info (CreatureDisplayInfo.dbc, CreatureModelData.dbc)
+  - Class and race info (ChrClasses.dbc, ChrRaces.dbc)
+  - Skill lines (SkillLine.dbc, SkillLineAbility.dbc)
+  - Faction and reputation (Faction.dbc)
+  - Map and area names (Map.dbc, AreaTable.dbc)
 
 ### 7. UI System (`src/ui/`)
 
 **UIManager** - ImGui coordinator
-- ImGui initialization
-- Event handling
-- Render dispatch
+- ImGui initialization with SDL2/OpenGL backend
+- Event handling and input routing
+- Render dispatch with opacity control
+- Screen state management
 
 **AuthScreen** - Login interface
-- Username/password input
+- Username/password input fields
 - Server address configuration
-- Connection status
+- "Single Player" offline mode button
+- Connection status and error messages
 
 **RealmScreen** - Server selection
-- Realm list display
-- Population info
-- Realm type (PvP/PvE/RP)
+- Realm list display with names and types
+- Population info (Low/Medium/High/Full)
+- Realm type indicators (PvP/PvE/RP/RPPvP)
+- Auto-select for single realm
 
 **CharacterScreen** - Character selection
-- Character list with 3D preview
-- Create/delete characters
+- Character list with 3D animated preview
+- Stats panel (level, race, class, location)
+- Create/delete character buttons
 - Enter world button
+- Auto-select for single character
 
-**GameScreen** - In-game UI
-- Chat window
-- Action bars
-- Character stats
-- Minimap
+**CharacterCreateScreen** - Character creation
+- Race selection (all Alliance and Horde races)
+- Class selection (class availability by race)
+- Gender selection
+- Appearance customization (face, skin, hair, color, features)
+- Name input with validation
+- 3D character preview
+
+**GameScreen** - In-game HUD
+- Chat window with message history and formatting
+- Action bar (12 slots with icons, cooldowns, keybindings)
+- Target frame (name, level, health, hostile/friendly coloring)
+- Player stats (health, mana/rage/energy)
+- Minimap with quest markers
+- Experience bar
+
+**InventoryScreen** - Inventory management
+- Equipment paper doll (23 slots: head, shoulders, chest, etc.)
+- Backpack grid (16 slots)
+- Item icons with tooltips
+- Drag-drop to equip/unequip
+- Item stats and durability
+- Gold display
+
+**SpellbookScreen** - Spells and abilities
+- Tabbed interface (class specialties + General)
+- Spell icons organized by SkillLine
+- Spell tooltips (name, rank, cost, cooldown, description)
+- Drag-drop to action bar
+- Known spell tracking
+
+**QuestLogScreen** - Quest tracking
+- Active quest list
+- Quest objectives and progress
+- Quest details (description, objectives, rewards)
+- Abandon quest button
+- Quest level and recommended party size
+
+**TalentScreen** - Talent trees
+- Placeholder for talent system
+- Tree visualization (TODO)
+- Talent point allocation (TODO)
+
+**Settings Window** - Configuration
+- UI opacity slider
+- Graphics options (TODO)
+- Audio controls (TODO)
+- Keybinding customization (TODO)
+
+**Loading Screen** - Map loading progress
+- Progress bar with percentage
+- Background image (map-specific, TODO)
+- Loading tips (TODO)
+- Shown during world entry and map transitions
 
 ## Data Flow Examples
 
@@ -306,15 +410,21 @@ Renderer draws in next frame
 
 ## Threading Model
 
-Currently **single-threaded**:
+Currently **single-threaded** with async operations:
 - Main thread: Window events, update, render
-- Network I/O: Non-blocking in main thread
-- Asset loading: Synchronous in main thread
+- Network I/O: Non-blocking in main thread (event-driven)
+- Asset loading: Async terrain streaming (non-blocking chunk loads)
+
+**Async Systems Implemented:**
+- Terrain streaming loads ADT chunks asynchronously to prevent frame stalls
+- Network packets processed in batches per frame
+- UI rendering deferred until after world rendering
 
 **Future multi-threading opportunities:**
-- Asset loading thread pool (background texture/model loading)
+- Asset loading thread pool (background texture/model decompression)
 - Network thread (dedicated for socket I/O)
 - Physics thread (if collision detection is added)
+- Audio streaming thread
 
 ## Memory Management
 
@@ -326,21 +436,34 @@ Currently **single-threaded**:
 ## Performance Considerations
 
 ### Rendering
-- **Frustum culling:** Only render visible chunks
-- **Batching:** Group draw calls by material
+- **Frustum culling:** Only render visible chunks (terrain and WMO groups)
+- **Distance culling:** WMO groups culled beyond 160 units
+- **Batching:** Group draw calls by material and shader
 - **LOD:** Distance-based level of detail (TODO)
 - **Occlusion:** Portal-based visibility (WMO system)
+- **GPU skinning:** Character animation computed on GPU (256 bones)
+- **Instancing:** Future optimization for repeated models
 
 ### Asset Streaming
-- **Lazy loading:** Load chunks as player moves
-- **Unloading:** Free distant chunks
-- **Caching:** Keep frequently used assets in memory
+- **Async loading:** Terrain chunks load asynchronously (prevents frame stalls)
+- **Lazy loading:** Load chunks as player moves within streaming radius
+- **Unloading:** Free distant chunks automatically
+- **Caching:** Keep frequently used assets in memory (textures, models)
+- **Priority queue:** Load visible chunks first
 
 ### Network
 - **Non-blocking I/O:** Never stall main thread
 - **Packet buffering:** Handle multiple packets per frame
+- **Batch processing:** Process received packets in batches
+- **RC4 encryption:** Efficient header encryption (minimal overhead)
 - **Compression:** Some packets are compressed (TODO)
 
+### Memory Management
+- **Smart pointers:** Automatic cleanup, no memory leaks
+- **Object pooling:** Reuse particle objects (weather system)
+- **DBC caching:** Load once, access fast
+- **Texture sharing:** Same texture used by multiple models
+
 ## Error Handling
 
 - **Logging:** All errors logged with context
@@ -363,16 +486,31 @@ Currently hardcoded, future config system:
 - Packet serialization/deserialization
 - SRP math functions
 - Asset parsers with sample files
+- DBC record parsing
+- Inventory slot calculations
 
 **Integration Testing** (TODO):
 - Full auth flow against test server
 - Realm list retrieval
-- Character selection
+- Character creation and selection
+- Quest turn-in flow
+- Vendor transactions
 
 **Manual Testing:**
-- Visual verification of rendering
-- Performance profiling
+- Visual verification of rendering (terrain, water, models, particles)
+- Performance profiling (F1 performance HUD)
 - Memory leak checking (valgrind)
+- Online gameplay against TrinityCore/MaNGOS servers
+- Single-player mode functionality
+- UI interactions (drag-drop, click events)
+
+**Current Test Coverage:**
+- Full authentication flow tested against live servers
+- Character creation and selection verified
+- Quest system tested (accept, track, turn-in)
+- Vendor system tested (buy, sell)
+- Combat system tested (targeting, auto-attack, spells)
+- Inventory system tested (equip, unequip, drag-drop)
 
 ## Build System