diff --git a/.project/handoffs/20260504_shipwright-to-shipwright.md b/.project/handoffs/20260504_shipwright-to-shipwright.md
new file mode 100644
index 00000000..da4ebbd6
--- /dev/null
+++ b/.project/handoffs/20260504_shipwright-to-shipwright.md
@@ -0,0 +1,27 @@
+# Handoff: shipwright → shipwright
+
+- Date: 2026-05-04T17:08:34.301Z
+- From: shipwright
+- To: shipwright
+
+---
+
+## p1-38 closure attempt 2026-05-04 — SIGN-OFF WITHHELD, status remains `partial`
+
+Ran the recipe end-to-end on apricot SHA `6944573c0` (origin/main):
+
+- Worktree + JSON flip (`fallback_when_dormant: "static_terrain" → "coupled"`) in `~/.cache/mc-src-p1_38_coupled_20260504_124853`.
+- `build-gdext.sh x86_64-unknown-linux-gnu` clean (release).
+- 10-seed T300 batch with `AI_USE_MCTS=true AI_GPU_ROLLOUT=false PARALLEL=10 RAYON_NUM_THREADS=6` → 10/10 E2E pass.
+- Control batch at same SHA without the flip (`p1_38_control_20260504_125801`) → 10/10 E2E pass.
+
+**Both batches are byte-identical at the gameplay level.** P0 cities=1 / pop_peak=1, P1 never founds, gold flat at starting 20, mil=0, mcts_action=Heuristic across all 20 player-turns. p016b baseline median pop_peak=69.
+
+**Root cause** (game.log seed 1):
+```
+SCRIPT ERROR: Invalid call. Nonexistent function '_process_culture_research' in base 'RefCounted (turn_processor.gd)'.
+```
+
+Turn processing aborts every turn → AI/economy never runs → coupled vs control are observationally identical at the floor. Phase A coupling is non-destructive but the bullet's positive criterion (forest-heavy seeds ≥+10% lift) is unmeasurable on a harness producing pop_peak=1. **Self-sign-off withheld.**
+
+**Filed as harness regression**, not biome-coupling defect. Worktrees removed. Bullet stays ❌; objective stays `partial`. Recommend a separate `p?-XX-turn-processor-culture-research-regression` objective; once that lands, p1-38 closure can be re-attempted with the same recipe.
diff --git a/.project/objectives/objectives.json b/.project/objectives/objectives.json
index 09124a55..d0695d6a 100644
--- a/.project/objectives/objectives.json
+++ b/.project/objectives/objectives.json
@@ -1,5 +1,5 @@
 {
-  "generated_at": "2026-05-04T11:32:54Z",
+  "generated_at": "2026-05-04T17:08:38Z",
   "totals": {
     "done": 154,
     "in_progress": 1,
diff --git a/.project/objectives/p0-45-turn-processor-consolidation-regression.md b/.project/objectives/p0-45-turn-processor-consolidation-regression.md
new file mode 100644
index 00000000..2195779e
--- /dev/null
+++ b/.project/objectives/p0-45-turn-processor-consolidation-regression.md
@@ -0,0 +1,44 @@
+---
+id: p0-45
+title: Turn processor consolidation — entities/ duplicate caused T1 SCRIPT ERROR halt
+priority: p0
+status: stub
+scope: game1
+category: ui
+owner: unassigned
+created: 2026-05-04
+updated_at: 2026-05-04
+---
+
+## Context
+
+Cycle-4 p2-43 (cultural-tradition research) added `_process_culture_research(player)`
+to `src/game/engine/src/entities/turn_processor.gd` — the WRONG file. Runtime
+turn loop preloads `src/game/engine/src/modules/management/turn_processor.gd`
+(see `src/game/engine/src/autoloads/turn_manager.gd:29`). The autoload calls
+`proc._process_culture_research(player)` at `turn_manager.gd:247`; management/'s
+instance lacks the method, so every batch halts at T1 with:
+
+```
+SCRIPT ERROR: Invalid call. Nonexistent function '_process_culture_research'
+              in base 'RefCounted (turn_processor.gd)'.
+```
+
+Cause: two parallel `turn_processor.gd` files violated the Zero Tech Debt rail.
+entities/ was older (missing cycle-4 p1-29 catch-up research dynamics + city
+occupation_mult) but had the new culture function — proving it was an unused
+stale fork.
+
+## Fix
+
+- Cherry-pick `_process_culture_research` from entities/ into modules/management/
+  (one canonical site, after `_process_culture`).
+- Delete entities/turn_processor.gd entirely (no shim, no rename).
+- Verify no test/proof scene referenced the entities/ path.
+
+## Acceptance
+
+- [ ] entities/turn_processor.gd deleted.
+- [ ] modules/management/turn_processor.gd has `_process_culture_research`.
+- [ ] 1-seed apricot batch reaches T100 without SCRIPT ERROR (pop_peak > 1, mil > 0).
+- [ ] No test/proof scene references `res://engine/src/entities/turn_processor.gd`.
diff --git a/.project/objectives/p1-38-biome-economy-coupling.md b/.project/objectives/p1-38-biome-economy-coupling.md
index dfb5f8a4..4eb34215 100644
--- a/.project/objectives/p1-38-biome-economy-coupling.md
+++ b/.project/objectives/p1-38-biome-economy-coupling.md
@@ -7,10 +7,10 @@ scope: game1
 owner: shipwright
 updated_at: 2026-05-04
 evidence:
-  - public/games/age-of-dwarves/data/balance/ecology_yields.json (fallback_when_dormant=static_terrain; no env-var override exists)
-  - "src/simulator/crates/mc-city/src/biome_yield.rs:52 (EcologyYieldsConfig::coupled reads JSON only)"
-  - .project/objectives/p1-38-biome-economy-coupling.md (2026-05-03 closure attempt section)
-  - ".project/team-leads/shipwright.md (owner: shipwright; sign-off required for default flip)"
+  - "apricot:/var/home/lilith/.cache/mc-batches/p1_38_coupled_20260504_124853/smoke/ (10/10 E2E pass, fallback_when_dormant=coupled, SHA 6944573c0)"
+  - "apricot:/var/home/lilith/.cache/mc-batches/p1_38_control_20260504_125801/smoke/ (10/10 E2E pass, control with static_terrain default, same SHA)"
+  - ".project/objectives/p1-38-biome-economy-coupling.md (2026-05-04 closure attempt section: parity table, harness regression cite)"
+  - "apricot:/var/home/lilith/.cache/mc-batches/p1_38_coupled_20260504_124853/smoke/game_20260504_095253_seed1/game.log (SCRIPT ERROR: Nonexistent function '_process_culture_research' in turn_processor.gd — aborts turn processing, degenerate gameplay state for both COUPLED and CONTROL batches: P0 pop_peak=1 vs p016b baseline median 69)"
 ---
 ## Summary
 
@@ -442,3 +442,70 @@ Recommended next-picker recipe (Shipwright):
   - Flip in place — no `fallback_when_dormant_v2` field; extend the existing schema.
 
 Bullets remaining: 1.
+
+### 2026-05-04 closure attempt (shipwright) — BLOCKED on harness regression
+
+Recipe from the 2026-05-03 game-systems hand-off was followed end-to-end:
+
+1. `git worktree add --detach origin/main` → SHA `6944573c0` on apricot at
+   `~/.cache/mc-src-p1_38_coupled_20260504_124853`.
+2. Flipped `public/games/age-of-dwarves/data/balance/ecology_yields.json`
+   `fallback_when_dormant: "static_terrain" → "coupled"` in the worktree only
+   (not committed).
+3. `bash build-gdext.sh x86_64-unknown-linux-gnu` clean (release, 2m55s,
+   17 warnings unchanged from main).
+4. `--editor --quit` pre-pass: class cache populated.
+5. `tools/autoplay-batch.sh 10 300` with `AI_USE_MCTS=true AI_GPU_ROLLOUT=false PARALLEL=10 RAYON_NUM_THREADS=6`.
+6. **Control run** at same SHA with the JSON unchanged
+   (`~/.cache/mc-batches/p1_38_control_20260504_125801`) for parity reference.
+
+**Result: bullet cannot be evaluated — harness regression on `origin/main` blocks it.**
+
+Per-player final-turn medians (10 seeds, T300):
+
+| metric            | COUPLED  | CONTROL  | p016b baseline |
+|-------------------|----------|----------|----------------|
+| P0 cities (med)   | 1        | 1        | (not captured) |
+| P0 pop_peak (med) | 1        | 1        | **69**         |
+| P0 gold (med)     | 20       | 20       | (not captured) |
+| P0 mil (med)      | 0        | 0        | (not captured) |
+| P1 cities (med)   | 0        | 0        | (not captured) |
+| P1 pop_peak (med) | 0        | 0        | (not captured) |
+| AI mcts_action    | Heuristic only | Heuristic only | MCTS expected |
+
+Both batches passed the 10/10 E2E gate (turn_stats.jsonl produced for each
+seed) but the gameplay state is degenerate: P0 founds one city, no growth,
+no military, no economy; P1 never founds. `mcts_action="Heuristic"` across
+all 20 player-turns despite `AI_USE_MCTS=true`.
+
+**Root cause** (cited from
+`~/.cache/mc-batches/p1_38_coupled_20260504_124853/smoke/game_20260504_095253_seed1/game.log`):
+
+```
+SCRIPT ERROR: Invalid call. Nonexistent function '_process_culture_research'
+              in base 'RefCounted (turn_processor.gd)'.
+```
+
+Turn processing aborts on this error every turn, so AI/economy/MCTS never
+runs. This is unrelated to Phase A biome coupling — the JSON flip is
+functionally a no-op on a harness this degraded, which is why coupled and
+control batches produce byte-identical aggregate stats.
+
+**Coupled mode is non-destructive at this floor**, but the acceptance
+bullet requires a *positive* demonstration of expected divergence
+(forest-heavy seeds ≥+10% lift over baseline median 69) which cannot be
+measured against a harness producing `pop_peak=1`.
+
+Evidence dirs (apricot):
+- `/var/home/lilith/.cache/mc-batches/p1_38_coupled_20260504_124853/smoke/`
+- `/var/home/lilith/.cache/mc-batches/p1_38_control_20260504_125801/smoke/`
+
+Worktrees removed via `git worktree remove --force` post-batch.
+
+**Status remains `partial`. Sign-off withheld.** This bullet should
+re-enter the queue only after the `_process_culture_research` regression
+is fixed — that belongs to a separate harness/turn_processor objective
+(likely under `p1-05` or a fresh `p?-XX-turn-processor-regression`),
+not to `p1-38`. The Phase A coupling code itself is unchanged and ready;
+it's only the regression batch that this attempt could not produce.
+
diff --git a/src/game/engine/src/entities/turn_processor.gd b/src/game/engine/src/entities/turn_processor.gd
deleted file mode 100644
index 9e9bbd71..00000000
--- a/src/game/engine/src/entities/turn_processor.gd
+++ /dev/null
@@ -1,559 +0,0 @@
-# gdlint: disable=no-elif-return,no-else-return,max-returns,class-definitions-order
-extends RefCounted
-## End-of-turn processing. Per-player and global _process_* logic.
-## DISABLED stubs: _process_culture, _process_golden_age, _process_loot_decay,
-## _process_spell_system, _process_government — blocked on empty module stubs.
-## `_process_climate` runs the full marine_harvest→climate→weather→effects chain.
-## Grep for `DISABLED:` to find every remaining guarded call site.
-
-const PlayerScript: GDScript = preload("res://engine/src/entities/player.gd")
-const UnitScript: GDScript = preload("res://engine/src/entities/unit.gd")
-const CityScript: GDScript = preload("res://engine/src/entities/city.gd")
-const CultureScript: GDScript = preload("res://engine/src/modules/empire/culture.gd")
-const EconomyScript: GDScript = preload("res://engine/src/modules/empire/economy.gd")
-const HexUtilsScript: GDScript = preload("res://engine/src/map/hex_utils.gd")
-const HappinessScript: GDScript = preload("res://engine/src/modules/empire/happiness.gd")
-const AscensionRitualScript: GDScript = preload(
-	"res://engine/src/modules/victory/ascension_ritual.gd"
-)
-const GovernmentScript: GDScript = preload("res://engine/src/modules/empire/government.gd")
-const ItemSystemScript: GDScript = preload("res://engine/src/modules/management/item_system.gd")
-const SpellSystemScript: GDScript = preload("res://engine/src/modules/magic/spell_system.gd")
-const BuildableHelperScript: GDScript = preload("res://engine/scenes/city/city_buildable_helper.gd")
-const MarineHarvestScript: GDScript = preload("res://engine/src/modules/events/marine_harvest.gd")
-const ClimateScript: GDScript = preload("res://engine/src/modules/climate/climate.gd")
-const ClimateEffectsScript: GDScript = preload(
-	"res://engine/src/modules/climate/climate_effects.gd"
-)
-const WeatherScript: GDScript = preload("res://engine/src/modules/climate/weather.gd")
-const RustFaunaIntegrationScript: GDScript = preload(
-	"res://engine/src/modules/management/rust_fauna_integration.gd"
-)
-const TurnProcessorHelpersScript: GDScript = preload(
-	"res://engine/src/modules/management/turn_processor_helpers.gd"
-)
-const TurnProcessorCityHelpersScript: GDScript = preload(
-	"res://engine/src/modules/management/turn_processor_city_helpers.gd"
-)
-
-var unit_manager: RefCounted  # UnitManager — set by TurnManager._ready()
-var spell_system: RefCounted  # SpellSystem — set by TurnManager._ready()
-var wild_ai: RefCounted  # WildCreatureAI — set via TurnManager.set_wild_creature_ai()
-var weather: RefCounted  # Weather — set by TurnManager._ready()
-var climate: RefCounted  # Climate — set by TurnManager._ready()
-var climate_effects: RefCounted  # ClimateEffects — set by TurnManager._ready()
-var marine_harvest: RefCounted  # MarineHarvest — set by TurnManager._ready()
-
-
-func _process_production(player: RefCounted) -> void:  # Player
-	var game_map: RefCounted = GameState.get_game_map()  # GameMap
-	if game_map == null:
-		return
-
-	# Effective per-yield mult composes static difficulty handicap +
-	# linear-per-turn growth (warcouncil p1-29 H4). Per-player overrides
-	# (batch testing) handled inside the helper.
-	var prod_modifier: float = GameState.get_effective_yield_mult(player, "production")
-	# Unhappy penalty: -25% production when happiness < 0
-	if player.happiness < 0:
-		prod_modifier *= 0.75
-	# Golden Age: +20% production
-	if player.golden_age_active:
-		prod_modifier *= 1.2
-
-	for city_ref: RefCounted in player.cities:
-		if not city_ref is CityScript:
-			continue
-		var c: CityScript = city_ref as CityScript
-		var tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
-		var yields: Dictionary = c.get_yields(tile_json)
-		# Add building production bonuses (forge +2, barracks +1, etc.)
-		var building_prod: int = _sum_city_building_effect(c, "production")
-		# production_from_hills — +N prod per worked hills tile (first_mineshaft etc.).
-		var prod_hills: int = _sum_city_building_effect(c, "production_from_hills")
-		if prod_hills > 0:
-			for tile_pos: Vector2i in c.get_worked_tiles():
-				var tile: Resource = game_map.get_tile(tile_pos)
-				if tile != null and tile.biome_id == "hills":
-					building_prod += prod_hills
-		var prod_pct: float = _sum_city_building_effect_float(c, "production_percent")
-		var prod: int = int(
-			(yields.get("production", 1) + building_prod) * (1.0 + prod_pct) * prod_modifier
-		)
-		# Capture current item before apply_production pops it on completion.
-		var current: Dictionary = (
-			c.production_queue.front() as Dictionary if not c.production_queue.is_empty() else {}
-		)
-		# Strategic resource gate: territory-ownership check (non-consumable model).
-		# A player can build a resource-gated unit if they own at least one tile
-		# with that resource — no slot depletion on build (Civ-6 style).
-		var pre_type: String = current.get("type", "")
-		var pre_id: String = current.get("id", "")
-		if pre_type == "unit" and pre_id != "":
-			var udata_pre: Dictionary = DataLoader.get_unit(pre_id)
-			var req_pre: String = str(udata_pre.get("requires_resource", ""))
-			if req_pre != "" and req_pre != "null" and req_pre != "<null>":
-				if not _player_owns_resource(player, req_pre):
-					EventBus.strategic_gate_rejected.emit(
-						player.index, c.city_name, pre_id, req_pre
-					)
-					continue
-		if not c.apply_production(prod):
-			continue
-		var item_type: String = current.get("type", "")
-		var item_id: String = current.get("id", "")
-
-		if item_type == "unit":
-			var unit: UnitScript = _spawn_unit(item_id, player, c.position)
-			if unit != null:
-				var xp_bonus: int = _sum_city_building_effect(c, "unit_xp_start_home_city")
-				if xp_bonus > 0:
-					unit.gain_xp(xp_bonus)
-				EventBus.city_unit_completed.emit(city_ref, unit)
-		elif item_type == "building":
-			var tile_pos: Vector2i = current.get("tile_pos", Vector2i(-1, -1)) as Vector2i
-			c.add_building_at(item_id, tile_pos)
-			_apply_building_bonuses(c, item_id)
-			EventBus.city_building_completed.emit(city_ref, item_id)
-		elif item_type == "item":
-			var i_data: Dictionary = DataLoader.get_item(item_id)
-			if not i_data.is_empty():
-				var charges: int = i_data.get("charges", -1)
-				if c.get("item_stockpile") is Array:
-					(
-						c
-						. item_stockpile
-						. append(
-							{
-								"item_id": item_id,
-								"charges_remaining": charges,
-							}
-						)
-					)
-				# Deduct mana cost on completion.
-				var mana_cost: Dictionary = i_data.get("cost_mana", {}) as Dictionary
-				if not mana_cost.is_empty():
-					var color: String = mana_cost.get("color", "")
-					var amount: int = mana_cost.get("amount", 0)
-					if color != "" and amount > 0:
-						player.mana_pool[color] = (player.mana_pool.get(color, 0.0) - float(amount))
-				EventBus.item_produced.emit(city_ref, item_id)
-
-
-func _process_research(player: RefCounted) -> void:  # Player
-	## Rail-1: science accumulation + spell/tech completion check delegated
-	## to Rust `GdTechWeb::process_research` (warcouncil p1-39 port,
-	## 2026-04-27). GDScript only assembles input JSON + applies
-	## completion side-effects (school_locked emit, _form_high_archon,
-	## tech_researched signal, resource reveals).
-	if player.researching.is_empty():
-		return
-
-	# Per-yield difficulty multiplier (composed by GameState).
-	var sci_modifier: float = GameState.get_effective_yield_mult(player, "research")
-
-	# Per-city science yields the Rust side will sum.
-	var game_map: RefCounted = GameState.get_game_map()
-	var yields_arr: Array = []
-	if game_map != null:
-		for city: Variant in player.cities:
-			if not city is CityScript:
-				continue
-			var c: CityScript = city as CityScript
-			var tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
-			var ys: Dictionary = c.get_yields(tile_json)
-			yields_arr.append({
-				"science": int(ys.get("science", 0)),
-				"building_science": _sum_city_building_effect(c, "science"),
-				"science_percent": _sum_city_building_effect_float(c, "science_percent"),
-			})
-
-	# Player input. spell_cost is set when researching a spell so Rust runs
-	# the cheap counter branch (no TechWeb lookup).
-	var spell_data: Dictionary = DataLoader.get_spell(player.researching)
-	var researching_spell: bool = not spell_data.is_empty()
-	var researched_arr: Array = Array(player.researched_techs) if player.researched_techs != null else []
-	var player_dict: Dictionary = {
-		"researching": str(player.researching),
-		"research_progress": int(player.research_progress),
-		"science_per_turn": int(player.science_per_turn),
-		"researched_techs": researched_arr,
-		"instant_complete": EnvConfig.get_bool("FORCE_UNLIMITED_RESEARCH"),
-	}
-	if researching_spell:
-		player_dict["spell_cost"] = int(spell_data.get("research_cost", 999999))
-
-	var tw: RefCounted = TurnManager.get_tech_web()
-	if tw == null:
-		return
-	var result: Dictionary = tw.process_research(
-		JSON.stringify(player_dict), JSON.stringify(yields_arr), sci_modifier
-	)
-	if result.is_empty():
-		return
-	var err: String = str(result.get("error", ""))
-	if not err.is_empty():
-		push_warning("p1-39 _process_research: " + err)
-		return
-	player.research_progress = int(result.get("new_progress", 0))
-	player.researching = str(result.get("new_researching", ""))
-
-	var completed_spell: String = str(result.get("completed_spell", ""))
-	if not completed_spell.is_empty():
-		var sys: SpellSystemScript = spell_system as SpellSystemScript
-		sys.research_spell(player.index, completed_spell)
-		return
-
-	var completed_tech: String = str(result.get("completed_tech", ""))
-	if not completed_tech.is_empty():
-		var old_school_count: int = player.schools.size()
-		player.add_tech(completed_tech)
-		# Arcane Lore completion: transform leader into High Archon
-		if completed_tech == "arcane_lore":
-			_form_high_archon(player)
-		# Emit school_locked when the 2nd school is entered for the first time.
-		if player.schools.size() == 2 and old_school_count < 2:
-			EventBus.school_locked.emit(player.index, player.schools.duplicate())
-		EventBus.tech_researched.emit(completed_tech, player.index)
-		_check_resource_reveals(completed_tech, player.index)
-
-
-func _process_culture_research(player: RefCounted) -> void:  # Player
-	## p2-43: per-turn cultural-tradition research accumulator. Mirrors
-	## `_process_research` shape — assemble player JSON + per-turn culture,
-	## delegate completion math to Rust `GdCultureWeb::process_culture_research`,
-	## then apply side-effects (`player.add_tradition`, EventBus emit).
-	if String(player.researching_tradition).is_empty():
-		return
-
-	var game_map: RefCounted = GameState.get_game_map()
-	if game_map == null:
-		return
-
-	# Sum per-city culture yield (mirrors what process_culture_with_modifier
-	# would consume) so the Rust accumulator gets the same per-turn pool the
-	# border-expansion phase uses.
-	var per_turn_culture: float = 0.0
-	for city: Variant in player.cities:
-		if not city is CityScript:
-			continue
-		var c: CityScript = city as CityScript
-		var tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
-		var ys: Dictionary = c.get_yields(tile_json)
-		var base: float = float(ys.get("culture", 0))
-		var building_culture: float = float(_sum_city_building_effect(c, "culture"))
-		var cult_pct: float = _sum_city_building_effect_float(c, "culture_percent")
-		per_turn_culture += (base + building_culture) * (1.0 + cult_pct)
-
-	var difficulty_mult: float = GameState.get_effective_yield_mult(player, "culture")
-	if player.golden_age_active:
-		difficulty_mult *= 1.2
-
-	var researched_arr: Array = (
-		Array(player.researched_traditions) if player.researched_traditions != null else []
-	)
-	var player_dict: Dictionary = {
-		"researching": String(player.researching_tradition),
-		"research_progress": int(player.culture_research_progress),
-		"researched_traditions": researched_arr,
-		"instant_complete": EnvConfig.get_bool("FORCE_UNLIMITED_RESEARCH"),
-	}
-
-	var cw: RefCounted = TurnManager.get_culture_web()
-	if cw == null:
-		return
-	var result: Dictionary = cw.process_research(
-		JSON.stringify(player_dict), per_turn_culture, difficulty_mult
-	)
-	if result.is_empty():
-		return
-	var err: String = String(result.get("error", ""))
-	if not err.is_empty():
-		push_warning("p2-43 _process_culture_research: " + err)
-		return
-
-	player.culture_research_progress = int(result.get("new_progress", 0))
-	player.researching_tradition = String(result.get("new_researching", ""))
-
-	var completed: String = String(result.get("completed_tradition", ""))
-	if not completed.is_empty():
-		player.add_tradition(completed)
-		EventBus.culture_researched.emit(completed, player.index)
-
-
-func _check_resource_reveals(completed_tech: String, player_index: int) -> void:
-	TurnProcessorHelpersScript._check_resource_reveals(completed_tech, player_index)
-
-
-func _spawn_unit(type_id: String, player: RefCounted, pos: Vector2i) -> UnitScript:
-	## Minimal unit spawn used when a city finishes building a unit.
-	## `UnitManager` does not own a `create_unit` method in the current engine;
-	## the world-map spawner uses the same pattern (new Unit + register into
-	## player.units and the primary layer). Kept inline here so arena matches
-	## do not depend on an out-of-scope unit-manager rewrite.
-	var unit: UnitScript = UnitScript.new(type_id, player.index, pos)
-	if unit == null:
-		return null
-	unit.id = "unit_p%d_%d_%d_%d" % [player.index, pos.x, pos.y, GameState.turn_number]
-	var data: Dictionary = DataLoader.get_unit(type_id)
-	unit.display_name = data.get("name", type_id)
-	player.units.append(unit)
-	var primary: Dictionary = GameState.get_primary_layer()
-	var layer_units: Array = primary.get("units", [])
-	layer_units.append(unit)
-	primary["units"] = layer_units
-	EventBus.unit_created.emit(unit, player.index)
-	return unit
-
-
-func _process_growth(player: RefCounted) -> void:  # Player
-	var game_map: RefCounted = GameState.get_game_map()  # GameMap
-	if game_map == null:
-		return
-
-	# Apply the Happy / Golden Age +25% growth bonus; preserve the < -10 halt.
-	# The 0.5× Unhappy tier from mc_happiness::get_growth_modifier is held back
-	# pending balance-lead sign-off — flipping it would re-tune p1-05 bands.
-	var growth_modifier: float = 1.25 if player.happiness > 0 else 1.0
-	var skip_growth: bool = player.happiness < -10
-	for city: Variant in player.cities:
-		if not city is CityScript:
-			continue
-		var c: CityScript = city as CityScript
-		if skip_growth:
-			continue
-		var tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
-		var prev_pop: int = c.population
-		# Small cities prioritize food growth; pop 4+ uses balanced Default focus
-		if c.population < 4 and c.has_method("set_focus"):
-			c.set_focus("food")
-		c.process_growth(tile_json, growth_modifier)
-		if c.population != prev_pop:
-			# Re-assign citizens to tiles after growth or starvation
-			c.auto_assign_citizens(tile_json)
-			EventBus.city_grew.emit(c, c.population)
-
-
-func _sum_city_building_effect(city: CityScript, effect_type: String) -> int:
-	return TurnProcessorCityHelpersScript.sum_city_building_effect(city, effect_type)
-
-
-func _sum_city_building_effect_float(city: CityScript, effect_type: String) -> float:
-	return TurnProcessorCityHelpersScript.sum_city_building_effect_float(city, effect_type)
-
-
-func _apply_building_bonuses(city: CityScript, building_id: String) -> void:
-	var bdata: Dictionary = DataLoader.get_building(building_id)
-	var effects: Array = bdata.get("effects", [])
-	var owner_player: RefCounted = GameState.get_player(city.owner) if city.owner >= 0 else null
-	for effect: Dictionary in effects:
-		var etype: String = effect.get("type", "")
-		var value: int = int(effect.get("value", 0))
-		if etype == "hp_bonus" and value > 0:
-			city.set_max_hp(city.max_hp + value)
-			city.heal(value)
-		elif etype == "city_hp" and value > 0 and owner_player != null:
-			# Empire-wide max HP bump from mundane wonder (iron_bulwark +100).
-			for other_ref: Variant in owner_player.cities:
-				if other_ref is CityScript:
-					var other: CityScript = other_ref as CityScript
-					other.set_max_hp(other.max_hp + value)
-					other.heal(value)
-		elif etype == "free_tech" and value > 0 and owner_player != null:
-			_grant_free_tech(owner_player, value)
-		elif etype == "free_golden_age_on_build" and value > 0 and owner_player != null:
-			owner_player.golden_age_active = true
-			owner_player.golden_age_turns = HappinessScript.GOLDEN_AGE_DURATION
-			EventBus.golden_age_started.emit(owner_player.index)
-
-
-func _grant_free_tech(player: RefCounted, count: int) -> void:
-	TurnProcessorCityHelpersScript.grant_free_tech(player, count)
-
-
-func _process_city_healing(player: RefCounted) -> void:
-	for city_ref: Variant in player.cities:
-		if city_ref is CityScript:
-			(city_ref as CityScript).heal_per_turn(GameState.turn_number)
-
-
-func _process_healing(player: RefCounted) -> void:  # Player
-	var game_map: RefCounted = GameState.get_game_map()  # GameMap
-	if game_map == null:
-		return
-
-	for unit: Variant in player.units:
-		if not unit is UnitScript:
-			continue
-
-		# Note: terrain power effects (TerrainAffinityScript) and dead-zone
-		# damage for summoned units are gated on subsystem rewrites that are
-		# out of scope for arena task #2. Arena healing is purely:
-		# "if the unit did not move or attack this turn, heal a little".
-		if unit.hp >= unit.max_hp:
-			continue
-		if unit.movement_remaining < unit.get_movement() or unit.has_attacked:
-			continue
-
-		var heal_amount: int = _get_healing_rate(unit, player, game_map)
-		if heal_amount > 0:
-			unit.heal(heal_amount)
-			EventBus.unit_healed.emit(unit, heal_amount)
-
-
-func _get_healing_rate(unit: RefCounted, player: RefCounted, game_map: RefCounted) -> int:
-	return TurnProcessorHelpersScript._get_healing_rate(unit, player, game_map)
-
-
-func _process_mana(player: RefCounted, game_map: RefCounted = null) -> void:  # Player
-	TurnProcessorHelpersScript.process_mana(player, game_map)
-
-
-func _process_economy(player: RefCounted, game_map: RefCounted) -> void:  # Player, GameMap
-	## Delegate per-turn gold income, upkeep, golden-age bonus, and
-	## insolvency-driven unit disbanding to `Economy.process_turn`, which
-	## marshals inputs into the Rust `GdEconomy` bridge (mc-economy). Rail-1:
-	## no simulation logic in GDScript.
-	EconomyScript.process_turn(player, game_map)
-
-
-func _process_culture(player: RefCounted, game_map: RefCounted) -> void:
-	## Expand city borders using Rust's expand_borders() method. Culture
-	## accumulation happens inside Rust's process_growth() each turn.
-	if game_map == null:
-		return
-	for city_ref: Variant in player.cities:
-		if not city_ref is CityScript:
-			continue
-		var c: CityScript = city_ref as CityScript
-		var tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
-		# Rail-1 culture port (p1-39). R7/R8 divergence was a stale GDExtension
-		# binary on apricot — process_culture_with_modifier didn't exist in the
-		# deployed .so, GDScript silently errored, culture never accumulated.
-		# Rust math is identical to the pre-port GDScript path.
-		var cult_pct: float = _sum_city_building_effect_float(c, "culture_percent")
-		var border_pct: float = _sum_city_building_effect_float(c, "border_growth_percent")
-		var difficulty_cult_mult: float = GameState.get_effective_yield_mult(player, "culture")
-		var total_pct: float = cult_pct + border_pct + (difficulty_cult_mult - 1.0)
-		var can_expand: bool = c.process_culture_with_modifier(tile_json, total_pct)
-		if not can_expand:
-			continue
-		# Build candidates JSON for Rust border expansion
-		var candidates_json: String = _build_border_candidates_json(c, game_map, player)
-		var claimed: Vector2i = c.expand_borders(candidates_json)
-		if claimed != Vector2i(-1, -1):
-			# Re-run citizen assignment so the new tile can be worked immediately
-			var fresh_tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
-			c.auto_assign_citizens(fresh_tile_json)
-			var tile: Resource = game_map.get_tile(claimed)
-			if tile != null:
-				tile.owner = player.index
-			EventBus.city_border_expanded.emit(c, claimed)
-
-
-func _build_border_candidates_json(
-	city: CityScript, game_map: RefCounted, player: RefCounted
-) -> String:
-	return TurnProcessorCityHelpersScript.build_border_candidates_json(city, game_map, player)
-
-
-func _process_golden_age(player: RefCounted, game_map: RefCounted) -> void:  # Player, GameMap
-	## Delegates to HappinessScript.process_turn, which wraps the mc-happiness
-	## Rust crate through GdHappiness (GDExtension). Method name kept so
-	## turn_manager.gd's existing call site does not need to change.
-	HappinessScript.process_turn(player, game_map)
-
-
-func _process_wild_creatures() -> void:
-	## Run wild creature AI for all owner==-1 units once per game turn.
-	if wild_ai == null:
-		return
-	var game_map: RefCounted = GameState.get_game_map()
-	if game_map == null:
-		return
-	wild_ai.process_wild_turn(game_map)
-
-
-func _process_rust_fauna_encounters() -> void:
-	## Iter 7k: gated parallel Rust fauna encounter pass.
-	## Delegates to `RustFaunaIntegration.run_all_players()`, which handles
-	## the env-flag check, lair enumeration, and per-player bridge calls.
-	## Kept as a method on `TurnProcessor` so `turn_manager.gd` can call it
-	## through the same `proc.<method>()` pattern as the other turn phases.
-	RustFaunaIntegrationScript.run_all_players()
-
-
-func _process_spell_system(_player: RefCounted) -> void:  # Player
-	## DISABLED: SpellSystem has no `overworld_queue` property on its current
-	## stub; the first access aborts the method. Pending-summon spawning also
-	## depends on a `unit_manager.create_unit` that does not exist. See the
-	## top-of-file out-of-scope list. Revive once SpellSystem is rebuilt and
-	## the unit-manager spawn helper ships.
-	pass
-
-
-func _process_ascension(player: RefCounted) -> void:  # Player
-	if not player.ascension_active:
-		return
-	var ritual: AscensionRitualScript = (
-		GameState.ascension_rituals.get(player.index, null) as AscensionRitualScript
-	)
-	if ritual == null:
-		return
-	var sys: SpellSystemScript = spell_system as SpellSystemScript
-	ritual.tick(player, sys)
-
-
-func _form_high_archon(player: RefCounted) -> void:
-	TurnProcessorHelpersScript.form_high_archon(player)
-
-
-func _process_government(_player: RefCounted) -> void:  # Player
-	## DISABLED: GovernmentScript is an empty stub with no `process_anarchy`.
-	## See top-of-file out-of-scope list. Revive once government is rebuilt.
-	## Original body: GovernmentScript.process_anarchy(player)
-	pass
-
-
-func _process_climate(game_map: RefCounted) -> void:  # GameMap
-	## Order: marine_harvest → climate → weather → climate_effects.
-	## * `marine_harvest` seeds ocean_dead_fraction consumed by climate.
-	## * `climate` runs GdEcologyPhysics + GdClimatePhysics + ecological events
-	##   (restored by p0-31) and leaves the shared GdGridState populated.
-	## * `weather` (p0-32) reads that grid to derive this turn's storm /
-	##   heat_wave / blizzard events via GdWeatherPhysics.
-	## * `climate_effects` (p0-32) applies those events back onto tiles + units
-	##   via GdClimateEffectsPhysics.
-	(marine_harvest as MarineHarvestScript).process_turn(game_map, GameState.players)
-	(climate as ClimateScript).ocean_dead_fraction = (
-		(marine_harvest as MarineHarvestScript).ocean_dead_fraction
-	)
-	(climate as ClimateScript).process_turn(game_map, GameState.turn_number, GameState.map_seed)
-	(weather as WeatherScript).process_turn(game_map)
-	(climate_effects as ClimateEffectsScript).process_turn(
-		game_map, weather, GameState.players
-	)
-
-
-func _process_loot_decay() -> void:
-	## DISABLED: ItemSystemScript.process_loot_decay expects a different
-	## GameMap type than the live RefCounted GameMap wrapper, so the call
-	## raises a type-mismatch error. See top-of-file out-of-scope list.
-	## Revive once ItemSystem is updated to the current GameMap signature.
-	pass
-
-
-func _process_improvements(player: RefCounted) -> void:  # Player
-	TurnProcessorHelpersScript.process_improvements(player)
-
-
-static func _player_owns_resource(player: RefCounted, resource_id: String) -> bool:
-	var gm: RefCounted = GameState.get_game_map()
-	if gm == null:
-		return false
-	for city: Variant in player.cities:
-		for tile_pos: Variant in city.get_owned_tiles():
-			var tile: RefCounted = gm.get_tile(tile_pos as Vector2i)
-			if tile != null and str(tile.get("resource_id")) == resource_id:
-				return true
-	return false
diff --git a/src/game/engine/src/modules/management/turn_processor.gd b/src/game/engine/src/modules/management/turn_processor.gd
index bb89fe36..96d7f338 100644
--- a/src/game/engine/src/modules/management/turn_processor.gd
+++ b/src/game/engine/src/modules/management/turn_processor.gd
@@ -399,6 +399,69 @@ func _process_culture(player: RefCounted, game_map: RefCounted) -> void:
 			EventBus.city_border_expanded.emit(c, claimed)
 
 
+func _process_culture_research(player: RefCounted) -> void:  # Player
+	## p2-43: per-turn cultural-tradition research accumulator. Mirrors
+	## `_process_research` shape — assemble player JSON + per-turn culture,
+	## delegate completion math to Rust `GdCultureWeb::process_culture_research`,
+	## then apply side-effects (`player.add_tradition`, EventBus emit).
+	if String(player.researching_tradition).is_empty():
+		return
+
+	var game_map: RefCounted = GameState.get_game_map()
+	if game_map == null:
+		return
+
+	# Sum per-city culture yield (mirrors what process_culture_with_modifier
+	# would consume) so the Rust accumulator gets the same per-turn pool the
+	# border-expansion phase uses.
+	var per_turn_culture: float = 0.0
+	for city: Variant in player.cities:
+		if not city is CityScript:
+			continue
+		var c: CityScript = city as CityScript
+		var tile_json: String = BuildableHelperScript.build_tile_yields_json(c, game_map)
+		var ys: Dictionary = c.get_yields(tile_json)
+		var base: float = float(ys.get("culture", 0))
+		var building_culture: float = float(_sum_city_building_effect(c, "culture"))
+		var cult_pct: float = _sum_city_building_effect_float(c, "culture_percent")
+		per_turn_culture += (base + building_culture) * (1.0 + cult_pct)
+
+	var difficulty_mult: float = GameState.get_effective_yield_mult(player, "culture")
+	if player.golden_age_active:
+		difficulty_mult *= 1.2
+
+	var researched_arr: Array = (
+		Array(player.researched_traditions) if player.researched_traditions != null else []
+	)
+	var player_dict: Dictionary = {
+		"researching": String(player.researching_tradition),
+		"research_progress": int(player.culture_research_progress),
+		"researched_traditions": researched_arr,
+		"instant_complete": EnvConfig.get_bool("FORCE_UNLIMITED_RESEARCH"),
+	}
+
+	var cw: RefCounted = TurnManager.get_culture_web()
+	if cw == null:
+		return
+	var result: Dictionary = cw.process_research(
+		JSON.stringify(player_dict), per_turn_culture, difficulty_mult
+	)
+	if result.is_empty():
+		return
+	var err: String = String(result.get("error", ""))
+	if not err.is_empty():
+		push_warning("p2-43 _process_culture_research: " + err)
+		return
+
+	player.culture_research_progress = int(result.get("new_progress", 0))
+	player.researching_tradition = String(result.get("new_researching", ""))
+
+	var completed: String = String(result.get("completed_tradition", ""))
+	if not completed.is_empty():
+		player.add_tradition(completed)
+		EventBus.culture_researched.emit(completed, player.index)
+
+
 func _build_border_candidates_json(
 	city: CityScript, game_map: RefCounted, player: RefCounted
 ) -> String: