Hygiene B3: single-sourcing & magic-number consolidation

- StructureCatalogAuthoring: WallCostOre -> WallCostBiomass (it bakes a Biomass cost; [FormerlySerializedAs] preserves the scene value).
- Harvester/Fabricator authoring: resource-id byte defaults reference ResourceId.Ore/.Charge instead of magic 2/4.
- RegionMath.RegionBoundaryX (= ExpeditionOffsetX*0.5) single-sources the region-flip X used by HudSystem + OnboardingSystem (was 500f in 3 places).
- CharacterComponent.DefaultGroundedSharpness single-sources the CC sharpness 15f (GetDefault, DashSystem, PlayerDeathStateSystem, PlayerCharacterAuthoring).
- InventorySlot [InternalBufferCapacity] references Tuning.InventoryMaxSlots.
- ConnectionMode enum -> byte-const class (project convention; removes the latent enum-in-Burst trap); field + one Seed() param become byte.
- Tuning.ChargerWindupTicks single-sources the Charger telegraph windup (EnemyBaker + TuningConfig.Defaults; was a bare 30 that could drift).
- (TicksPerSecond deliberately NOT added: no seconds->ticks conversion site exists; the tick-count fields are per-authoring designer tunables, so a const would be unreferenced.)

451/451 EditMode tests pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Assets/_Project/Scripts/Simulation/Player/DashSystem.cs

@@ -32,7 +32,7 @@ namespace ProjectM.Simulation
         // Feel knobs are LIVE-tunable via the TuningConfig singleton (MC-0): OnUpdate reads it each tick and falls
         // back to TuningConfig.Defaults() when absent (release builds / EditMode), so behaviour is identical to the
         // old baked consts. DefaultSharpness (the restore target) + SimTickRate stay compile-time (not tuned).
-        const float DefaultSharpness = 15f;  // CharacterComponent.GetDefault() base
+        const float DefaultSharpness = CharacterComponent.DefaultGroundedSharpness;  // CharacterComponent.GetDefault() base
         const float SimTickRate = 60f;
 
         [BurstCompile]