fix(pi): prepare runtime state and agent workdir

tests/unit/test_docker_bottle.py

@@ -41,6 +41,15 @@ def _pi_bottle(prompt_path: str | None = None) -> DockerBottle:
     )
 
 
+def _workspace_bottle() -> DockerBottle:
+    return DockerBottle(
+        container="bot-bottle-dev-abc",
+        teardown=lambda: None,
+        prompt_path_in_container=None,
+        agent_workdir="/home/node/workspace",
+    )
+
+
 class TestClaudeArgv(unittest.TestCase):
     def test_minimal_argv_no_prompt(self):
         argv = _bottle().agent_argv([])
@@ -89,6 +98,16 @@ class TestClaudeArgv(unittest.TestCase):
             argv,
         )
 
+    def test_workspace_workdir_is_used_when_set(self):
+        argv = _workspace_bottle().agent_argv([])
+        self.assertEqual(
+            [
+                "docker", "exec", "-it", "-w", "/home/node/workspace",
+                "bot-bottle-dev-abc", "claude",
+            ],
+            argv,
+        )
+
     def test_caller_argv_not_mutated(self):
         # `agent_argv` builds `full_argv` from a copy, so a
         # caller passing a long-lived list (e.g., the dashboard's