Replace hardcoded WotLK protocol constants with a data-driven architecture
supporting Classic 1.12.1, TBC 2.4.3, and WotLK 3.3.5a. Each expansion
has JSON profiles for opcodes, update fields, and DBC layouts, plus C++
polymorphic packet parsers for binary format differences (movement flags,
speed fields, transport data, spline format, char enum layout).
Key components:
- ExpansionRegistry: scans Data/expansions/*/expansion.json at startup
- OpcodeTable: logical enum <-> wire values loaded from JSON
- UpdateFieldTable: field indices loaded from JSON per expansion
- DBCLayout: schema-driven DBC field lookups replacing magic numbers
- PacketParsers: WotLK/TBC/Classic parsers with correct flag positions
- Multi-manifest AssetManager: layered manifests with priority ordering
- HDPackManager: overlay texture packs with expansion compatibility
- Auth screen expansion picker replacing hardcoded version dropdown
Add complete Blizzard-style time-of-day lighting pipeline:
Spatial Volume System (Light.dbc):
- Light volumes with position + inner/outer radius
- Distance-based weighting with smoothstep falloff
- Multi-volume blending (top 2 with normalized weights)
- X,Z,Y coordinate handling + LIGHT_COORD_SCALE for ×36 quirk
- Smooth zone transitions without popping
Profile Selection (LightParams.dbc):
- Weather variants: clear/rain/underwater
- Links to 18 color + 6 float band curves per profile
- Block indexing: LightParamsID × 18/6 + channel
Time-of-Day Band Sampling (LightIntBand/LightFloatBand):
- Half-minutes format (0-2879) with time clamping
- Keyframe interpolation with midnight wrap
- Wrap-safe initialization for edge cases
- BGR color unpacking
Multi-Volume Blending:
- Weighted sum of all lighting params
- Proper direction blending: normalize(sum(dir × weight))
- Blends ambient, diffuse, fog, sky, cloud density
Temporal Smoothing:
- Exponential blend to prevent frame snapping
- Smooths ALL parameters (colors, fog, direction, sky)
Game Time Support:
- Accepts server-sent game time (WoW standard)
- Falls back to local time if not provided
- Manual override for testing
Debug Features:
- Volume distance/weight logging
- Fog params logging
- Coordinate scale verification
Also: Move buff bar to top-left under player frame
