feat(docker): add Makefile with verify target and exit code validation

Added:
- Makefile with verify target that runs docker compose
- New 'verify' stage in Dockerfile for automated testing
- Added rentgen_verify service to compose.yml
- Verification exits with proper exit code (0=success, non-zero=failure)

The make verify command:
1. Builds extension with docker compose
2. Runs test_verify.sh in headless Firefox
3. Propagates exit code from verification script
4. Fails if no proof of code execution found

Usage: make verify

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Dockerfile

@@ -56,3 +56,13 @@ RUN chmod +x /app/test_start_extension.sh
 
 # Start script
 CMD ["/app/test_start_extension.sh"]
+
+# Verify stage - automated testing with exit code
+FROM runtime AS verify
+
+# Copy verification script
+COPY scripts/test_verify.sh /app/test_verify.sh
+RUN chmod +x /app/test_verify.sh
+
+# Run verification and exit with proper exit code
+CMD ["/app/test_verify.sh"]

Makefile

@@ -0,0 +1,20 @@
+.PHONY: verify clean help
+
+# Default target - run verification
+verify:
+	@echo "Building and verifying Rentgen extension..."
+	docker compose up --force-recreate --build --abort-on-container-exit --exit-code-from rentgen_verify
+	@echo "✓ Verification completed successfully!"
+
+# Clean up Docker resources
+clean:
+	docker compose down --rmi local --volumes --remove-orphans
+
+# Help target
+help:
+	@echo "Rentgen Extension - Makefile"
+	@echo ""
+	@echo "Available targets:"
+	@echo "  make verify  - Build and verify extension (exits with error if verification fails)"
+	@echo "  make clean   - Clean up Docker resources"
+	@echo "  make help    - Show this help message"

compose.yml

@@ -8,3 +8,9 @@ services:
             target: runtime
         stdin_open: true
         tty: true
+
+    rentgen_verify:
+        build:
+            context: .
+            target: verify
+        restart: "no"