fix: add SSH key selection to workspace tool starter + docker compose policy

tool-starter.tsx was hardcoding ssh_key_ids=[] and only showing a read-only
SSH key status. Users couldn't select keys when starting tools from workspaces.

Changes:
- tool-starter.tsx: add checkboxes for SSH key selection with repo key
  pre-selected, pass selected keys to createInstance/startInstance
- AGENTS.md: add explicit rule forbidding docker compose commands without
  user approval and proper isolation

The web container must be rebuilt to pick up the frontend changes:
  docker compose up -d --build web

Quality gates: tsc clean, pytest (19 passed, 1 skipped)

apps/api/src/services/terminal_session.py

@@ -187,9 +187,7 @@ class TerminalSession:
         try:
             data = os.read(self._master_fd, 4096)
         except (OSError, IOError) as exc:
-            logger.debug(
-                "PTY read error for session %s: %s", self.session_id, exc
-            )
+            logger.debug("PTY read error for session %s: %s", self.session_id, exc)
             self._handle_eof()
             return
 
@@ -320,7 +318,9 @@ class TerminalSession:
         self._websockets.clear()
         for ws in dead_sockets:
             try:
-                asyncio.create_task(ws.close(code=4001, reason="Session process exited"))
+                asyncio.create_task(
+                    ws.close(code=4001, reason="Session process exited")
+                )
             except Exception:
                 pass
         logger.info("Session %s EOF handled, websockets closed", self.session_id)
@@ -333,9 +333,7 @@ class TerminalSession:
             os.write(self._master_fd, data)
             self.last_activity = time.time()
         except (OSError, IOError) as exc:
-            logger.debug(
-                "PTY write error for session %s: %s", self.session_id, exc
-            )
+            logger.debug("PTY write error for session %s: %s", self.session_id, exc)
             self._handle_eof()
 
     def _set_terminal_size(self, cols: int, rows: int) -> None: