Phase 4 — Trees, Rocks, Items, Stockpiles, Hauling

Three gdscript-refactor agents in parallel + Opus integration.

Entities (scenes/entities/, Agent A — 3 scripts + 3 .tscn, ~460 lines):
- item.gd: 16-type StringName registry (matches design.md filter chips);
  Node2D + _draw() colored square + stack-count badge; to_dict/from_dict
- tree.gd: class_name HarvestableTree (Godot 4 ships a built-in 'Tree'
  Control class — renamed to avoid the shadow); CHOP_TICKS=80; on_chop_tick
  advances progress, fells when complete, drops 3 wood items at tile +
  walkable neighbours
- rock.gd: MINE_TICKS=120; angular polygon _draw; mined() drops 1 stone

Toil + provider extensions (scenes/ai/, Agent B — 4 files modified/added,
~250 lines):
- Toil: new KIND_INTERACT (timed entity action), KIND_PICKUP, KIND_DEPOSIT
- JobRunner: _tick_interact resolves NodePath, calls target.<method>()
  each tick, marks done when is_choppable/is_mineable returns false;
  _tick_pickup finds Item at pawn.tile, transfers to pawn.carried_item;
  _tick_deposit places carried_item at pawn.tile + clears the
  items_needing_haul dirty flag
- ChopProvider (priority=5): nearest choppable tree; Job=[walk_to + interact]
- MineProvider (priority=4): same for rocks

Hauling system (scenes/world/ + scenes/ai/, Agent C — 4 files, ~330 lines):
- StorageDestination: abstract Node2D base; Priority enum CRITICAL=0..OFF=4;
  accepted_types (empty=wildcard); _filter_accepts() helper
- StockpileZone: concrete rect-region zone; _draw paints priority-tinted
  overlay (z_index=-1); find_drop_position scans for free cells respecting
  one-stack-per-tile rule
- HaulingProvider (priority=3): nearest dirty item × best destination →
  4-toil job [walk → pickup → walk → deposit]; sweep_for_better_destinations
  enables the priority cascade (items in lower-priority zones re-mark dirty
  when a higher-priority destination opens up)

Opus integration (~200 lines):
- World autoload: trees/rocks/items/items_needing_haul/stockpiles registries
  + register/unregister methods; pathfinder reference exposed for entity
  code (tree.fell needs is_walkable for neighbour drops)
- Pawn: carried_item slot + carry-indicator (small colored rect upper-right
  of body) via queue_redraw in _on_sim_tick
- World scene: registers chop/mine/haul/rest providers; spawns 6 trees
  (cluster east-north), 4 rocks (south-east), 2 stockpile zones (Zone A
  wood-only NORMAL, Zone B wildcard HIGH); periodic
  hauling_provider.sweep_for_better_destinations every 100 sim ticks

Acceptance — MCP-verified end-to-end (the full Phase 4 loop):
- 3 pawns boot, Decision picks chop (highest priority work), all walk to
  nearest tree, chop in parallel (3× speed because all 3 call on_chop_tick
  per tick). Trees fell, drop wood (18 items). Pawns move to rocks, mine,
  drop stone (4 items). Total 22 items spawn.
- HaulingProvider routes wood + stone toward Zone B (wildcard HIGH > Zone
  A's wood-only NORMAL). Pawns carry items one at a time, visual indicator
  shows during transit. Items deposit, items_needing_haul dirty flag
  clears.
- **Priority cascade test:** Zone A promoted from NORMAL to CRITICAL.
  Manually-triggered sweep marks 3 wood items in Zone B for re-haul.
  Within a few thousand ticks: Zone A has 5 wood (cascaded from Zone B),
  Zone B has 4 stone only (wood left, stone stayed because Zone A rejects
  stone). Filter + priority cascade working exactly per design.md spec.

Phase 4 gotchas (logged in implementation.md):
- 'Tree' shadows Godot 4's built-in Tree Control class — class_name had to
  be renamed to HarvestableTree. Scene/file names stayed as 'tree' since
  the game concept is still 'tree'; the rename only affects code-side
  type references.
- draw_colored_polygon(points, color) takes a SINGLE Color, not a
  PackedColorArray. Agent C had to be reminded; draw_polygon(points, colors)
  is the variant that takes per-vertex colors.
- Godot's class-name cache lags behind file changes — a full editor scan
  ('godot --headless --editor --quit') is needed to flush. Even after
  reload_project, type-annotation assignments can fail; duck-typed
  variables ('var x = scene.instantiate()') sidestep the issue.
- JobRunner's _tick_deposit had to explicitly call
  World.clear_item_haul_flag — the dirty set persisted otherwise and
  items appeared 'needing haul' even after deposit.

Delegation report this phase:
- Agent A (Sonnet, gdscript-refactor): Tree + Rock + Item entities + i18n
  keys. ~460 lines.
- Agent B (Sonnet, gdscript-refactor): Toil extensions + JobRunner handlers
  + ChopProvider + MineProvider. ~250 lines.
- Agent C (Sonnet, gdscript-refactor): StorageDestination + StockpileZone
  + HaulingProvider with cascade sweep. ~330 lines.
- Opus: World autoload extensions (entity registries + pathfinder ref),
  Pawn carry slot + visual, world.tscn/gd wiring, the Tree rename, the
  draw_colored_polygon fix, the dirty-set-clear fix, MCP-driven runtime
  verification including the full chop-mine-haul loop and the priority
  cascade demo.

~75% of Phase 4's GDScript was subagent-authored.

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

scenes/entities/rock.gd

@@ -0,0 +1,147 @@
+## Rock entity — mineable by a pawn with a Mine job. Drops a stone Item node
+## when mined out.
+##
+## Mirrors Tree's chopping model; stone is harder so MINE_TICKS is longer.
+## A MineProvider (Opus, Phase 4) creates a Job whose INTERACT toil calls
+## on_mine_tick() once per sim tick via JobRunner.
+##
+## World registration (World.register_rock / World.unregister_rock) is called
+## here but the methods land in World during Opus integration.
+
+class_name Rock extends Node2D
+
+const TILE_SIZE_PX: int = 16
+
+## Sim ticks to mine a rock at 1× speed (120 ticks = 6 sim seconds at 20 Hz).
+## Stone is harder than wood — MINE_TICKS > Tree.CHOP_TICKS.
+const MINE_TICKS: int = 120
+## Stone Items dropped on a successful mine.
+const STONE_DROPS_ON_MINE: int = 1
+
+# ── state ─────────────────────────────────────────────────────────────────────
+
+var tile: Vector2i = Vector2i.ZERO
+## 0..MINE_TICKS. Advanced by on_mine_tick(); rock is mined when equal to MINE_TICKS.
+var mine_progress: int = 0
+
+# Preloaded scene for spawned stone items.
+const ITEM_SCENE: PackedScene = preload("res://scenes/entities/item.tscn")
+
+
+# ── lifecycle ─────────────────────────────────────────────────────────────────
+
+func _ready() -> void:
+	position = _tile_to_world(tile)
+	World.register_rock(self)
+
+
+func _exit_tree() -> void:
+	World.unregister_rock(self)
+
+
+# ── public API ────────────────────────────────────────────────────────────────
+
+## One-shot initialiser. Call after add_child() so _ready() already fired.
+func setup(start_tile: Vector2i) -> void:
+	tile = start_tile
+	mine_progress = 0
+	position = _tile_to_world(tile)
+	queue_redraw()
+	Audit.log("rock", "spawned at %s" % tile)
+
+
+## True when the rock hasn't been fully mined yet.
+func is_mineable() -> bool:
+	return mine_progress < MINE_TICKS
+
+
+## Called by the INTERACT toil in JobRunner once per sim tick while the pawn
+## works this rock. Advances mine_progress and triggers mined() when complete.
+func on_mine_tick() -> void:
+	if not is_mineable():
+		return
+	mine_progress += 1
+	queue_redraw()
+	if mine_progress >= MINE_TICKS:
+		mined()
+
+
+## Drop stone Item(s) and free this node. Called automatically by on_mine_tick()
+## but also accessible for scripted removal (debug, storyteller events).
+func mined() -> void:
+	# Single drop lands on the rock's own tile.
+	var item: Item = ITEM_SCENE.instantiate()
+	get_parent().add_child(item)
+	item.setup(Item.TYPE_STONE, 1, tile)
+	Audit.log("rock", "mined at %s; %d stone drop" % [tile, STONE_DROPS_ON_MINE])
+	queue_free()
+
+
+# ── save / load ───────────────────────────────────────────────────────────────
+
+func to_dict() -> Dictionary:
+	return {
+		"tile_x": tile.x,
+		"tile_y": tile.y,
+		"mine_progress": mine_progress,
+	}
+
+
+static func from_dict(d: Dictionary) -> Dictionary:
+	return {
+		"tile_x": int(d.get("tile_x", 0)),
+		"tile_y": int(d.get("tile_y", 0)),
+		"mine_progress": int(d.get("mine_progress", 0)),
+	}
+
+
+# ── render ────────────────────────────────────────────────────────────────────
+
+func _draw() -> void:
+	# Angular cluster of 3–4 triangles in a dark-grey / light-grey palette.
+	var c1 := Color(0.55, 0.55, 0.50)   # light face
+	var c2 := Color(0.38, 0.38, 0.36)   # shadow face
+
+	# Main body polygon (roughly an irregular hex).
+	var body := PackedVector2Array([
+		Vector2(-5.0, 3.0),
+		Vector2(-6.0, -1.0),
+		Vector2(-2.0, -6.0),
+		Vector2(3.0, -5.0),
+		Vector2(6.0, 0.0),
+		Vector2(4.0, 4.0),
+	])
+	draw_colored_polygon(body, c1)
+
+	# Shadow face on the bottom-right triangle to give depth.
+	var shadow := PackedVector2Array([
+		Vector2(3.0, -5.0),
+		Vector2(6.0, 0.0),
+		Vector2(4.0, 4.0),
+		Vector2(-5.0, 3.0),
+	])
+	draw_colored_polygon(shadow, c2)
+
+	# Outline.
+	draw_polyline(body, Color(0.0, 0.0, 0.0, 0.5), 1.0)
+	draw_line(body[5], body[0], Color(0.0, 0.0, 0.0, 0.5), 1.0)
+
+	# Mine-progress crack: a dark jagged line on the face when partially mined.
+	if mine_progress > 0:
+		var ratio := float(mine_progress) / float(MINE_TICKS)
+		var crack_len := ratio * 5.0
+		draw_line(
+			Vector2(-1.0, -2.0),
+			Vector2(-1.0 + crack_len, 1.0),
+			Color(0.15, 0.12, 0.10, 0.85),
+			1.5
+		)
+
+
+# ── helpers ───────────────────────────────────────────────────────────────────
+
+func _tile_to_world(t: Vector2i) -> Vector2:
+	return Vector2(
+		t.x * TILE_SIZE_PX + TILE_SIZE_PX / 2.0,
+		t.y * TILE_SIZE_PX + TILE_SIZE_PX / 2.0
+	)