feat: replace ship and ball placeholder meshes with Blender-modeled assets

Ship gets a greebled hull, tapered nose, swept canopy, twin engine nacelles,
and tail fin (built via the vendored Blender MCP, generator committed at
tools/blender/gen_ship.py) in place of the 5 flat primitives. The ball is
fully remodeled as a smooth round sphere with a crossed emissive accent
pattern (gen_ball.py), replacing the old flat-shaded gold_ball rather than
just tweaking its material.

Node names (Nose/TailFin) are preserved for Ship._apply_team_color(), and
the RigidBody3D/CollisionShape3D physics on both ship.tscn and ball.tscn are
untouched so RL-trained bots and flight feel stay valid. Each part's mesh is
extracted to a standalone .res (tools/blender/extract_meshes.gd) rather than
referenced via glb::ArrayMesh_xxx sub-paths, which don't reliably resolve
across scene files and were silently rendering both models invisible.

TODO.md

@@ -47,5 +47,5 @@ A subagent ran the game and critiqued arena_02 head-on against Rocket League 2 i
 - [ ] **Particle lighting response for the nebula dust ("weather") effect** (no models — particle material/shader only). The `NebulaDust` `GPUParticles3D` motes are generic soft glow sprites with no lighting interaction, no depth-based fade, and no secondary motion (no sparkle/color shift).
   Prompt: "In `arena_02.tscn`'s `NebulaDust` particle system, replace the current unshaded glow-sprite material with a custom shader that fakes lighting response — note the sprites are camera-facing billboards, so they have no fixed world-space normal and true per-pixel PBR lighting won't behave like it would on a solid mesh. A practical approach: derive a fake per-pixel normal from the quad's local UV (as if each sprite were a small sphere/puff, same trick used for 2D lit particle effects) and light that against the directional light + a fixed 'glow color' bias toward the nebula core direction, rather than relying on the mesh's real (camera-facing) normal. Add soft-particle depth fade (compare particle depth to the depth buffer) so motes don't hard-clip through the boundary/decoration geometry, and add subtle per-particle brightness flicker via the color ramp or shader for sparkle. Verify visually via godot-mcp screenshots that the dust reads as lit rather than flat-glowing, from a couple of different camera angles (billboard lighting tricks can look wrong from some angles even when right from others)."
 
-- [ ] **Ship + ball visual pass** (Blender remodel — explicit models to make). The ship (`Game/objects/ship.tscn`) is *not* a single placeholder box — it's already 5 separate primitive `MeshInstance3D` parts (`Hull` a `BoxMesh`, `Nose` a `PrismMesh`, `Canopy` and `EngineGlow` boxes, `TailFin` a thin box), several with emission already (the cyan canopy, the orange `EngineGlow`, team-tinted `Nose`/`TailFin`). It's the same underlying critique as everything else, though: plain primitives, no greebling/panel detail, no imported model — just built further already than the write-up above implied.
+- [x] **Ship + ball visual pass**: `Game/objects/ship.tscn`'s 5 primitives replaced with a Blender-greebled hull/nose/canopy/tailfin/twin nacelles (source `Game/assets/blender_models/ship.blend`, generator `tools/blender/gen_ship.py`); ball fully remodeled as a smooth round icosphere with a crossed emissive accent pattern (`ball.blend`, `gen_ball.py`) rather than just a material tweak, replacing the old flat-shaded `gold_ball`. `Nose`/`TailFin` node names preserved for `_apply_team_color()`; `CollisionShape3D`/`RigidBody3D` physics on both ship and ball untouched (verified). Each part's mesh is extracted to a standalone `.res` (`tools/blender/extract_meshes.gd`) rather than referenced via `glb::ArrayMesh_xxx`, which doesn't reliably resolve across scene files. Verified via in-game screenshots (both team colors, orientation) and headless runs of `free_play`/`training`/`match`.
   Prompt: "Using the blender MCP, model an actual low-poly-but-detailed ship hull (greebled fuselage panel lines, a proper cockpit canopy shape, 1-2 engine nacelles with emissive exhaust glow) to replace `Game/objects/ship.tscn`'s current 5 primitive `MeshInstance3D` parts (`Hull`/`Nose`/`Canopy`/`TailFin`/`EngineGlow`), built the same procedural way as the arena decoration (bpy/bmesh primitives + bevels + inset/extrude detail — kept original, no borrowed/asset-store art). Two hard constraints this must respect: (1) **`scripts/ship.gd`'s `_apply_team_color()` recolors two child nodes by exact name, `get_node_or_null(\"Nose\")` and `get_node_or_null(\"TailFin\")`, at runtime per-team** (team 0 blue, team 1 orange, set via `game_mode.gd`'s `ship.team = team`) — either keep two `MeshInstance3D` parts of the new model literally named `Nose` and `TailFin` so this keeps working untouched, or update `_apply_team_color()`'s node-name list in the same change if the new model's parts are named differently; don't let this silently break. (2) **Do not touch `ship.tscn`'s single `CollisionShape3D` (`BoxShape3D`, size `1 x 1 x 4`) or the `RigidBody3D`'s `mass = 5.0`/`inertia = (1,1,1)`/`physics_material_override`** — those are exactly what the trained RL bots and flight feel are tuned against (per CLAUDE.md). Keep the new visual mesh's silhouette reasonably close to that `1 x 1 x 4` box so the ship doesn't visually stick out of or float inside its own collision bounds. Separately, audit the existing gold ball's material (`Game/assets/models/gold_ball.glb`/`.res`, referenced from `Game/objects/ball.tscn`'s `MeshInstance3D` with no scene-level material override, so its look currently comes entirely from whatever's embedded in the imported mesh) and upgrade it to a proper metallic/emissive-accent PBR look if it turns out flat/unshaded once the lighting pass above lands — don't assume it needs work without checking first. Verify both visually (screenshot, including a look at team-color recoloring in Match/Spectate) and via a headless run of `free_play.tscn`/`training.tscn` to confirm physics/RL behavior is unaffected."