Turrets: 40 Ore + per-base cap of 6 + fit-one-cell textured model (fix cheap/spam/massive/untextured)

Operator: turrets were "super duper cheap", spammable "unlimited", "spaced weirdly", "massive and not textured".
All four were real and independently rooted (placement grid was actually fine).

- Cost: TurretCostOre 10 -> 40 (authoring default + the serialized Gameplay subscene value, which overrides the
  code default). A node yields 30 Ore, so a turret is now ~1.3 nodes instead of 1/3 of one.
- Cap: new Tuning.TurretCap=6, enforced server-authoritatively in BuildPlaceSystem (count live Base turrets while
  building the occupancy set; reject placement at the cap, same-tick-safe). Was unlimited.
- Model: the 1.6x Synty ballista (~5m on a 1m cell, clipping neighbours) scaled to 0.8 to fit one cell; the C5
  BoxCollider shrunk to match (0.8x1.2x0.8, center y 0.6); all 6 sub-renderers swapped off the flat untextured
  teal Mat_StructureOwned_Cyan to the Synty atlas PolygonFantasyKingdom_Mat_01_A (textured). Play-verified
  TurretCost=40 Ore / cap=6 baked; no exceptions.

Also fixes 3 EditMode tests that pinned the old dash knobs (the prior tuning commit changed iframe 12->14 /
cooldown 45->36 but I committed it without re-running tests): DashSystemTests now derives the expected dash speed
from TuningConfig.Defaults() (robust to future tuning) + asserts now+14/+36; TuningConfigTests pins the new
defaults. 390/390 EditMode green.

Investigation: wf_c6c87dc5-9c3 (turret lane). Operator fork: 40 Ore + cap 6 (stricter).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/_Project/Scripts/Authoring/Building/StructureCatalogAuthoring.cs

@@ -18,7 +18,7 @@ namespace ProjectM.Authoring
         public GameObject TurretPrefab;
 
         [Tooltip("Ore cost to build a turret.")]
-        [Min(0)] public int TurretCostOre = 10;
+        [Min(0)] public int TurretCostOre = 40; // DR-042 combat pass: was 10 (~1/3 node) -> 40 (~1.3 nodes); a real investment
 
         [Tooltip("Wall structure ghost prefab (StructureAuthoring{Wall} + GhostAuthoring).")]
         public GameObject WallPrefab;