feat: implement tool workshop - comprehensive tool system enhancement

- Add Docker Compose and Dockerfile support for tool definitions
- Implement readiness probes with configurable command, timeout, interval
- Create ConfigFolder model for reusable file collections with project overrides
- Add rich tool config fields: port_override, start_command, working_directory, env vars, volumes
- Build unified Tool Workshop UI at /tool-workshop replacing /tool-configs and /tool-types
- Update instance creation to support dockerfile builds, config folder mounting, readiness probes
- Add 3 database migrations for tool_types, tool_configs, and new config_folders table
- Create docker_build.py and readiness_probe.py services
- Add config_folders API with CRUD and project override endpoints

Quality gates: frontend build passes, Python syntax valid, all phases complete

Addresses tool-workshop OpenSpec change

apps/api/src/services/readiness_probe.py

@@ -0,0 +1,66 @@
+"""Readiness probe service for checking if containers are ready."""
+
+import asyncio
+import logging
+import subprocess
+
+logger = logging.getLogger(__name__)
+
+
+async def execute_probe(
+    container_id: str,
+    command: str,
+    timeout: int = 30,
+    interval: int = 2,
+) -> tuple[bool, list[str]]:
+    """Execute a readiness probe command inside a container.
+
+    Args:
+        container_id: Docker container ID or name
+        command: Command to execute inside the container
+        timeout: Maximum total time to wait (seconds)
+        interval: Time between retries (seconds)
+
+    Returns:
+        Tuple of (success, logs)
+    """
+    logs = []
+    start_time = asyncio.get_event_loop().time()
+    attempt = 0
+
+    while True:
+        attempt += 1
+        elapsed = asyncio.get_event_loop().time() - start_time
+        
+        if elapsed >= timeout:
+            logs.append(f"Probe timed out after {timeout}s ({attempt} attempts)")
+            return False, logs
+
+        try:
+            logger.debug("Probe attempt %d: %s", attempt, command)
+            
+            # Execute command inside container
+            result = subprocess.run(
+                ["docker", "exec", container_id, "sh", "-c", command],
+                capture_output=True,
+                text=True,
+                timeout=interval,  # Each attempt has its own timeout
+            )
+            
+            if result.returncode == 0:
+                logs.append(f"Attempt {attempt}: Success")
+                if result.stdout:
+                    logs.append(f"Output: {result.stdout.strip()}")
+                return True, logs
+            else:
+                logs.append(f"Attempt {attempt}: Failed (exit code {result.returncode})")
+                if result.stderr:
+                    logs.append(f"Stderr: {result.stderr.strip()[:200]}")
+                
+        except subprocess.TimeoutExpired:
+            logs.append(f"Attempt {attempt}: Command timed out")
+        except Exception as exc:
+            logs.append(f"Attempt {attempt}: Error - {exc}")
+
+        # Wait before next attempt
+        await asyncio.sleep(interval)