Remove the dead Slay-the-Spire map system (superseded by the lobby)

The lobby hub replaced the between-fights map, leaving the whole map
subsystem unused. Remove it:

- Delete MapScreen.tscn + map_screen.gd (the dead screen) and map_node.gd
  (the MapNode class).
- Strip map generation + navigation from run_state.gd (~90 lines:
  _generate_map/_link_rows/reachable/select_node/node_at/current_node/
  run_complete/complete_current_level, plus map/player_row/col/pending_row/col).
  ensure_run() now guards on a _run_active flag instead of the map array, so
  the shell reloading for each fight still can't wipe the run in progress.
- Simplify active_level() to the lobby flow (override -> lobby -> gate -> arena).
- Drop the now-unread LevelDef.color / is_boss fields and the _make_level args.
- Remove the map test from logic_test.gd.

Live flow unchanged (lobby gates via choose_level, wins via return_to_lobby).
Full headless suite green; menu + shell boot into the lobby clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FBbGXbzg3SD6ZBSadPPF5H

CLAUDE.md

@@ -52,10 +52,8 @@ art/                            all raw art, grouped by role (snake_case):
 | `actors/bear/bear.tscn` / `actors/bear/bear.gd` | Dark-Souls-style bear boss (`CharacterBody3D`). Routine state machine (wind-up → active → recovery) picking telegraphed moves by range band: Double Swipe / Overhead Smash (close), Leap Slam (mid-far), plus Stalk (2-leg walk-in) / Prowl (4-leg lope) positioning. Melee steps in during the swing (`bear_lunge_speed`) + tracks the bull; the leap is frame-synced to JUMP_SMASH so the paws hit ground on the impact frame (`bear_leap_impact_frame`); slams kick up dust + shake. Combos chain, hyper-armour mid-swing + poise (`bear_stagger_cd`), phase 2 enrage under `bear_enrage_frac` HP. Never damages the bull by colliding — only swings/slams. A horns-first bull charge wounds it (`_sweep_bull_ram`: swept prev→now so a tunnelling/point-blank charge still lands, gated by `bear_ram_reach` + `bull_gore_arc`, edge-triggered = one charge per wound). Joins `&"matador"` so bull abilities already hit it. Tuning under the `Bear` DP section |
 | `actors/bear/bear_attack_hitboxes.tscn` | The bear's attack colliders as a self-contained sub-scene (instanced under `bear_model`): a `LeapSlamHitbox` (Hitbox + cylinder = ground circle) and `SmashHitbox` (Hitbox + box = forward shockwave lane), plus an `AnimationPlayer` whose `leap_slam` / `smash_travel` clips author each collider's size + travel — scrub to tweak, like `Bear_FX`. `actors/bear/bear.gd` only fires the clip, arms the knock-up shaping, and sweeps for overlaps while it runs (see `_setup_attack_hitboxes` / `_start_attack_hitbox`) |
 | `actors/matador/sword.tscn` / `systems/combat/hitbox.gd` | The matador's sword wrapper (glb + editor-tweakable `BladeHitbox`). `systems/combat/hitbox.gd` (`class_name Hitbox`, Area3D) is the shared attack collider: `activate()`/`deactivate()` gate an active window, `sweep()` catches bodies already inside (AoE), and knock-up can ramp by distance (`knock_up_min_dist`/`_max_dist`) for the bear's outer-ring launch / further-hit-flies-higher |
-| `levels/run_state.gd` | Run progression autoload (`Run`) — Slay-the-Spire map + player position across fights |
-| `levels/level_def.gd` | `LevelDef` resource — a level's name / map colour / `scene_path` (always the shell) / `level_scene` (the level module instanced into the shell) / optional `enemy_scene` (arena wave vs. a boss like the bear) |
-| `levels/map_node.gd` | `MapNode` — one runtime node on the run map (position, level, links) |
-| `levels/MapScreen.tscn` / `levels/map_screen.gd` | Between-fights map screen; win → pick a node → next level |
+| `levels/run_state.gd` | Run progression autoload (`Run`) — the lobby hub and which level is being fought, across scene reloads |
+| `levels/level_def.gd` | `LevelDef` resource — a level's name / `scene_path` (always the shell) / `level_scene` (the level module instanced into the shell) / optional `enemy_scene` (arena wave vs. a boss like the bear) |
 | `systems/crowd/crowd_marker.gd` | `CrowdMarker` (`@tool Node3D`, `class_name`) — designer drops one per billboard spectator via the editor's Add-Node dialog; picks one of six 60°-spaced facings from the `orientation` dropdown. Draws an editor-only preview (slab + forward arrow, never serialised) and joins the `&"crowd_marker"` group |
 | `systems/crowd/crowd_billboards.gd` / `systems/crowd/crowd_billboard.gdshader` | `MultiMeshInstance3D` that harvests every `CrowdMarker` (group `&"crowd_marker"`) into one draw call, using each marker's world position + chosen facing. Front/back sprite sheet baked by `tools/bake_crowd_sheet.gd`; falls back to a generated inward-facing ring when no markers are placed |
 | `systems/debug/debug_params.gd` | Runtime-tunable parameter registry (autoload `DP`). Mobile-relevant flags: `force_touch_controls`, `touch_debug` (also enabled on-device with `?debug=1` in the page URL — shows the live profiler overlay in `systems/input/touch_controls.gd`), and `use_rigid_skin` (default **off** — native GPU skinning everywhere now that the 4.7 web templates fixed the Mali/ANGLE invisible-skinning bug; `systems/render/rigid_skin.gd` is a retained opt-in fallback). Rigid-skin is gated through `Controls.rigid_skin_enabled()`, which a page URL param overrides for on-device A/B with no console: `?skin=1` forces the workaround on (for a device where native skinning still fails), `?noskin=1` forces native off. Turning the workaround off also removes its per-spawn SurfaceTool rebuild, which was the arena's matador-spawn lag |