Merge pull request #1: feat(client): Godot 4 project boilerplate (epic #277)

Merge origin/client into main. Resolve binary conflict in
commonwealth.db by keeping main's version (latest ticket state).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Makefile

@@ -1,3 +1,5 @@
+GODOT := $(shell command -v godot4 2>/dev/null || command -v godot 2>/dev/null)
+
 .PHONY: help setup build client server test lint ci ci-client ci-server clean \
        decisions-sync decisions-coverage decisions-active decisions-orphan
 
@@ -52,8 +54,8 @@ build-server:
 	cd server && cargo build
 
 build-client:
-	@echo "Client build: Godot exports are configured via the editor."
-	@echo "Use 'make client' to run the client directly."
+	@test -n "$(GODOT)" || { echo "Godot not found. Run 'make setup' first."; exit 1; }
+	$(GODOT) --headless --path client --quit
 
 # --- Run ---
 
@@ -61,13 +63,8 @@ server:
 	cd server && cargo run
 
 client:
-	@if command -v godot4 >/dev/null 2>&1; then \
-		godot4 --path client; \
-	elif command -v godot >/dev/null 2>&1; then \
-		godot --path client; \
-	else \
-		echo "Godot not found. Run 'make setup' first."; exit 1; \
-	fi
+	@test -n "$(GODOT)" || { echo "Godot not found. Run 'make setup' first."; exit 1; }
+	$(GODOT) --path client
 
 # --- Test ---
 
@@ -77,8 +74,8 @@ test-server:
 	cd server && cargo nextest run
 
 test-client:
-	@echo "Client tests run via gdUnit4 inside Godot."
-	@echo "TODO: headless test runner integration"
+	@test -n "$(GODOT)" || { echo "Godot not found. Run 'make setup' first."; exit 1; }
+	$(GODOT) --headless --path client -s res://addons/gdUnit4/bin/GdUnitCmdTool.gd --ignoreHeadlessMode -a res://tests/
 
 # --- Lint ---
 
@@ -89,7 +86,9 @@ lint-server:
 	cd server && cargo fmt --check
 
 lint-client:
-	@echo "Client lint: TODO — gdlint / gdformat integration"
+	@test -n "$(GODOT)" || { echo "Godot not found. Run 'make setup' first."; exit 1; }
+	@echo "Checking GDScript for errors..."
+	@$(GODOT) --headless --path client --quit 2>&1 | grep -i "SCRIPT ERROR" && { echo "GDScript errors found"; exit 1; } || echo "No script errors found"
 
 # --- CI (run locally) ---
 
@@ -118,4 +117,5 @@ decisions-orphan:
 clean:
 	cd server && cargo clean || true
 	rm -rf .cache/*
+	rm -rf client/.godot client/reports
 	@echo "Clean complete."