feat: headless_prompt method on AgentProvider + --prompt arg

tests/unit/test_cli_start_headless.py

@@ -77,26 +77,48 @@ class TestCmdStartHeadless(unittest.TestCase):
     # -- no TUI in headless --------------------------------------------
 
     def test_headless_fires_no_pickers(self):
-        rc = start_mod.cmd_start(["--headless", "researcher", "--bottle", "claude"])
+        rc = start_mod.cmd_start(
+            ["--headless", "researcher", "--bottle", "claude", "--prompt", "Do it"]
+        )
         self.assertEqual(0, rc)
         self._agent_picker.assert_not_called()
         self._bottle_picker.assert_not_called()
         self._modal.assert_not_called()
 
     def test_headless_assume_yes_forwarded(self):
-        start_mod.cmd_start(["--headless", "researcher", "--bottle", "claude"])
+        start_mod.cmd_start(
+            ["--headless", "researcher", "--bottle", "claude", "--prompt", "Do it"]
+        )
         self.assertTrue(self._launch_mock.call_args[1]["assume_yes"])
 
+    # -- prompt --------------------------------------------------------
+
+    def test_headless_without_prompt_dies(self):
+        with self.assertRaises(Die):
+            start_mod.cmd_start(["--headless", "researcher", "--bottle", "claude"])
+        self._launch_mock.assert_not_called()
+
+    def test_headless_prompt_forwarded_to_launch(self):
+        start_mod.cmd_start(
+            ["--headless", "researcher", "--bottle", "claude",
+             "--prompt", "Implement issue #42"]
+        )
+        self.assertEqual(
+            "Implement issue #42",
+            self._launch_mock.call_args[1]["headless_prompt_text"],
+        )
+
     # -- bottle resolution ---------------------------------------------
 
     def test_explicit_bottles_forwarded_in_order(self):
         start_mod.cmd_start(
-            ["--headless", "researcher", "--bottle", "dev", "--bottle", "claude"]
+            ["--headless", "researcher", "--bottle", "dev", "--bottle", "claude",
+             "--prompt", "Do it"]
         )
         self.assertEqual(("dev", "claude"), self._spec().bottle_names)
 
     def test_omitted_bottle_falls_back_to_agent_default(self):
-        start_mod.cmd_start(["--headless", "implementer"])
+        start_mod.cmd_start(["--headless", "implementer", "--prompt", "Do it"])
         self.assertEqual(("claude",), self._spec().bottle_names)
 
     def test_no_bottle_and_no_default_dies(self):
@@ -105,7 +127,9 @@ class TestCmdStartHeadless(unittest.TestCase):
             "bot_bottle.cli.start.ManifestIndex.resolve", return_value=manifest
         ):
             with self.assertRaises(Die):
-                start_mod.cmd_start(["--headless", "researcher"])
+                start_mod.cmd_start(
+                    ["--headless", "researcher", "--prompt", "Do it"]
+                )
         self._launch_mock.assert_not_called()
 
     # -- agent resolution ----------------------------------------------
@@ -118,19 +142,23 @@ class TestCmdStartHeadless(unittest.TestCase):
     def test_unknown_agent_raises_manifest_error(self):
         self._manifest.require_agent.side_effect = ManifestError("agent 'x' not defined")
         with self.assertRaises(ManifestError):
-            start_mod.cmd_start(["--headless", "x", "--bottle", "claude"])
+            start_mod.cmd_start(
+                ["--headless", "x", "--bottle", "claude", "--prompt", "Do it"]
+            )
         self._launch_mock.assert_not_called()
 
     # -- label / color -------------------------------------------------
 
     def test_label_defaults_to_agent_name(self):
-        start_mod.cmd_start(["--headless", "researcher", "--bottle", "claude"])
+        start_mod.cmd_start(
+            ["--headless", "researcher", "--bottle", "claude", "--prompt", "Do it"]
+        )
         self.assertEqual("researcher", self._spec().label)
 
     def test_explicit_label_and_color_forwarded(self):
         start_mod.cmd_start(
             ["--headless", "researcher", "--bottle", "claude",
-             "--label", "nightly", "--color", "green"]
+             "--label", "nightly", "--color", "green", "--prompt", "Do it"]
         )
         spec = self._spec()
         self.assertEqual("nightly", spec.label)
@@ -141,14 +169,17 @@ class TestCmdStartHeadless(unittest.TestCase):
             "bot_bottle.cli.start.enumerate_active_agents",
             return_value=[_active_agent("researcher")],
         ):
-            start_mod.cmd_start(["--headless", "researcher", "--bottle", "claude"])
+            start_mod.cmd_start(
+                ["--headless", "researcher", "--bottle", "claude", "--prompt", "Do it"]
+            )
         self.assertEqual("researcher-2", self._spec().label)
 
     # -- backend wiring ------------------------------------------------
 
     def test_backend_flag_forwarded(self):
         start_mod.cmd_start(
-            ["--headless", "--backend=docker", "researcher", "--bottle", "claude"]
+            ["--headless", "--backend=docker", "researcher", "--bottle", "claude",
+             "--prompt", "Do it"]
         )
         self.assertEqual("docker", self._launch_mock.call_args[1]["backend_name"])