fix: broken tests and stale .env.example

- Fix container-runner bug: stopContainer() returns void but was
  passed to exec() as a command string. Replace with direct call
  and try/catch.
- Mock container-runtime in tests so they don't need Docker running.
- Increase claw-skill test timeout to handle slower python startup.
- Clear .env.example (telegram token was added by mistake).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/container-runner.ts

@@ -2,7 +2,7 @@
  * Container Runner for NanoClaw
  * Spawns agent execution in containers and handles IPC
  */
-import { ChildProcess, exec, spawn } from 'child_process';
+import { ChildProcess, spawn } from 'child_process';
 import fs from 'fs';
 import path from 'path';
 
@@ -431,15 +431,15 @@ export async function runContainerAgent(
         { group: group.name, containerName },
         'Container timeout, stopping gracefully',
       );
-      exec(stopContainer(containerName), { timeout: 15000 }, (err) => {
-        if (err) {
-          logger.warn(
-            { group: group.name, containerName, err },
-            'Graceful stop failed, force killing',
-          );
-          container.kill('SIGKILL');
-        }
-      });
+      try {
+        stopContainer(containerName);
+      } catch (err) {
+        logger.warn(
+          { group: group.name, containerName, err },
+          'Graceful stop failed, force killing',
+        );
+        container.kill('SIGKILL');
+      }
     };
 
     let timeout = setTimeout(killOnTimeout, timeoutMs);