feat(rendering): implement spell visual effects with bone-tracked ribbons and particles

Add complete spell visual pipeline resolving the DBC chain
(Spell → SpellVisual → SpellVisualKit → SpellVisualEffectName → M2)
with precast/cast/impact phases, bone-attached positioning, and
automatic dual-hand mirroring.

Ribbon rendering fixes:
- Parse visibility track as uint8 (was read as float, suppressing
  all ribbon edges due to ~1.4e-45 failing the >0.5 check)
- Filter garbage emitters with bone=UINT_MAX unconditionally
- Guard against NaN spine positions from corrupt bone data
- Resolve ribbon textures via direct index, not textureLookup table
- Fall back to bone 0 when ribbon bone index is out of range

Particle rendering fixes:
- Reduce spell particle scale from 5x to 1.5x (was oversized)
- Exempt spell effect instances from position-based deduplication

Spell handler integration:
- Trigger precast visuals on SMSG_SPELL_START with server castTimeMs
- Trigger cast/impact visuals on SMSG_SPELL_GO
- Cancel precast visuals on cast interrupt/failure/movement

M2 classifier expansion:
- Add AmbientEmitterType enum for sound system integration
- Add 20+ foliage tokens, 4 spell effect tokens, isSmallFoliage flag
- Add markModelAsSpellEffect() to override disableAnimation

DBC layouts:
- Add SpellVisualID field to Spell.dbc for all expansion configs

Signed-off-by: Pavel Okhlopkov <pavel.okhlopkov@flant.com>

src/rendering/m2_renderer_render.cpp

@@ -46,7 +46,8 @@ uint32_t M2Renderer::createInstance(uint32_t modelId, const glm::vec3& position,
 
     // Deduplicate: skip if same model already at nearly the same position.
     // Uses hash map for O(1) lookup instead of O(N) scan.
-    if (!mdlRef.isGroundDetail) {
+    // Spell effects are exempt — transient visuals must always create fresh instances.
+    if (!mdlRef.isGroundDetail && !mdlRef.isSpellEffect) {
         DedupKey dk{modelId,
                     static_cast<int32_t>(std::round(position.x * 10.0f)),
                     static_cast<int32_t>(std::round(position.y * 10.0f)),
@@ -111,7 +112,8 @@ uint32_t M2Renderer::createInstance(uint32_t modelId, const glm::vec3& position,
     }
 
     // Register in dedup map before pushing (uses original position, not ground-adjusted)
-    if (!mdlRef.isGroundDetail) {
+    // Spell effects are exempt from dedup tracking (transient, overlapping allowed).
+    if (!mdlRef.isGroundDetail && !mdlRef.isSpellEffect) {
         DedupKey dk{modelId,
                     static_cast<int32_t>(std::round(position.x * 10.0f)),
                     static_cast<int32_t>(std::round(position.y * 10.0f)),