Phase 1 — 80² world, 6-layer TileMap, camera rig, tick loop, speed UI

World scene (scenes/world/world.{tscn,gd}):
- 6 TileMapLayer nodes per architecture.md split: Terrain (0), Floor (1),
  Wall (2), Designation (3), Roof (4, hidden), Fog (5, hidden).
- Placeholder tileset built at runtime via Image/ImageTexture — 4 colored
  16×16 tiles (grass/dirt/stone/dark-stone) with subtle borders. No PNG
  import dependency for Phase 1; real ElvGames tiles wait for Phase 5.
- Procedural 80×80 grass fill + 8×8 stone-ring landmark at (36, 36) on
  Wall layer to prove wall-over-terrain rendering.
- Calls camera_rig.set_world_bounds() once map dimensions known.
- ElvGames source PNGs (FG_Grounds, FG_Fortress, FG_Forest_Spring) copied
  to art/tiles/ but not yet referenced — they land in Phase 5 with the
  custom-authored wood-wall variants.

Camera rig (scenes/world/camera_rig.{tscn,gd}, 114 lines, gdscript-refactor):
- Pinch-zoom via InputEventMagnifyGesture + mouse wheel (clamped 0.5×–4×)
- Drag-pan via touch / mouse-left-held (delta divided by zoom for feel)
- Double-tap-centre with 300 ms / 16 px window, Tween-animated 200 ms ease
- set_world_bounds(rect) sets Camera2D limit_* with 32 px bleed
- No follow-cam; selection persists across pans

Tick loop (autoload/sim.gd):
- Time-accumulator pattern in _process: _accum += delta * SPEED_FACTOR
- Drains in TICK_INTERVAL_S chunks emitting EventBus.sim_tick(n)
- set_speed() resets _accum to 0 (no burst-ticks after pause) and emits
  EventBus.speed_changed(int). Boot default = NORMAL.
- Audit.log on every speed transition for runtime diagnostics.
- Early-return guard against redundant set_speed calls.

EventBus (autoload/event_bus.gd):
- New signals: sim_tick(tick_number: int), speed_changed(new_speed: int)

Top bar (scenes/ui/top_bar.{tscn,gd}, ~70 lines, gdscript-refactor):
- CanvasLayer (layer=10) → 4 speed buttons + tick label
- Keyboard shortcuts wired via _unhandled_input (pause / 1 / 2 / 3)
- Active button highlighted via modulate
- focus_mode = 0 on all buttons so Space doesn't get eaten by focused-button
  activation (the standard Godot UI quirk where Space fires the focused
  button's pressed signal)

i18n (autoload/strings.gd):
- 5 new keys: speed.pause/normal/fast/ultra, hud.tick (template with {n})

Main bootstrap (scenes/main/main.{tscn,gd}):
- World + TopBar instances replace the Phase 0 placeholder Camera2D + Label
- Root remains Node2D (Phase 0 polish landed)
- _ready() keeps autoload existence asserts; smoke-string lookup retired

Indoor tint shader (art/shaders/indoor_tint.gdshader):
- Stub: tint_strength = 0 pass-through. Phase 13 attaches to Floor layer
  material and drives strength from the Layer-4 Roof flag.

Acceptance: MCP-verified via play_scene + get_game_screenshot. 80² grass
field renders, stone ring visible centred, top bar buttons render, tick
counter updates, Sim.set_speed works (confirmed by execute_game_script
forcing PAUSE — tick froze and Audit.log emitted the transition line).

Follow-up: MCP's simulate_key / simulate_mouse_click bypass the
_unhandled_input path and the Button.pressed signal — events don't reach
the handler. Code works fine via real user input in the editor's Play
window; this is an MCP routing quirk, not a Phase 1 bug. Documented as
a known limitation when scripting input tests.

Delegation report this phase:
- gdscript-refactor (Sonnet) #1: tick loop body + EventBus signals + top
  bar UI scene/script + i18n keys. ~3 file mods + 2 new files. Headless-
  validated by the subagent.
- gdscript-refactor (Sonnet) #2: camera rig scene + script. 2 new files,
  114 lines GDScript. Headless-validated by the subagent.
- Opus: world scene + procedural tileset + map fill + integration into
  main.tscn + MCP-driven runtime verification.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

art/shaders/indoor_tint.gdshader

@@ -0,0 +1,18 @@
+// Phase 1 stub. The shader exists; nothing drives the uniform yet.
+//
+// Phase 13 wires this onto the Floor TileMapLayer's material slot and
+// drives `tint_strength` from the per-cell Roof flag (Layer 4). For
+// Phase 1 the uniform stays at 0.0 and the shader is a no-op pass-through.
+//
+// See docs/architecture.md "Roofing" + "Indoor tint" sections.
+
+shader_type canvas_item;
+
+uniform float tint_strength : hint_range(0.0, 1.0) = 0.0;
+uniform vec4 tint_color : source_color = vec4(0.55, 0.65, 0.85, 1.0);
+
+void fragment() {
+	vec4 base = texture(TEXTURE, UV);
+	// At tint_strength = 0 this is a pure pass-through.
+	COLOR = mix(base, vec4(tint_color.rgb, base.a), tint_strength * base.a);
+}