feat(git-gate+orchestrator): slice 13c(v) — provision git-gate into the running gateway

Places a bottle's git-gate credentials + bare repos into the live shared
gateway container when it registers — the execution side of the 13c(i)
provisioning render.

- provision_git_gate(gateway, bottle_id, plan): mkdir the per-bottle creds
  dir, docker cp each upstream's identity key (+ known_hosts when present)
  into /git-gate/creds/<bottle_id>/, then docker exec the namespaced,
  init-only script from git_gate_render_provision. No-op with no upstreams.
- deprovision_git_gate(gateway, bottle_id): rm the bottle's /git/<id> +
  creds on teardown (idempotent).
- bottle_id is validated (shell/path-safe alphabet) BEFORE any docker cp/rm,
  so a traversal id can never reach a path arg — the creds/repo dirs land in
  docker cp/rm arguments. Registry ids are token_hex; defense in depth.

pyright 0 errors; pylint 9.83/10; unit suite green (the 13 test_sidecar_init
/bin/sleep errors are pre-existing NixOS-local noise).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WBMWTEtQdJ4W5UrWuLHCck

tests/unit/test_gateway_provision.py

@@ -0,0 +1,111 @@
+"""Unit: git-gate provisioning into the running shared gateway (PRD 0070)."""
+
+from __future__ import annotations
+
+import unittest
+from pathlib import Path
+from unittest.mock import Mock, patch
+
+from bot_bottle.backend.docker.gateway_provision import (
+    GatewayProvisionError,
+    deprovision_git_gate,
+    provision_git_gate,
+)
+from bot_bottle.git_gate import GitGatePlan, GitGateUpstream
+
+_RUN = "bot_bottle.backend.docker.gateway_provision.run_docker"
+
+
+def _proc(returncode: int = 0, stderr: str = "") -> Mock:
+    return Mock(returncode=returncode, stderr=stderr)
+
+
+def _recorder(calls: list[list[str]]):
+    """A run_docker side_effect that records argv and returns success."""
+    def fake(argv: list[str]) -> Mock:
+        calls.append(argv)
+        return _proc()
+    return fake
+
+
+def _plan(*upstreams: GitGateUpstream) -> GitGatePlan:
+    return GitGatePlan(
+        slug="demo",
+        entrypoint_script=Path(),
+        hook_script=Path(),
+        access_hook_script=Path(),
+        upstreams=tuple(upstreams),
+    )
+
+
+def _up(name: str, *, key: str = "/host/keys/id", known_hosts: str = "") -> GitGateUpstream:
+    return GitGateUpstream(
+        name=name,
+        upstream_url=f"ssh://git@github.com/x/{name}.git",
+        upstream_host="github.com",
+        upstream_port="22",
+        identity_file=key,
+        known_host_key="",
+        known_hosts_file=Path(known_hosts) if known_hosts else Path(),
+    )
+
+
+class TestProvisionGitGate(unittest.TestCase):
+    def test_copies_creds_and_runs_namespaced_init(self) -> None:
+        calls: list[list[str]] = []
+        with patch(_RUN, side_effect=_recorder(calls)):
+            provision_git_gate("gw", "bottle1", _plan(_up("foo", known_hosts="/host/kh")))
+
+        cps = [c for c in calls if c[:2] == ["docker", "cp"]]
+        self.assertIn(["docker", "cp", "/host/keys/id", "gw:/git-gate/creds/bottle1/foo-key"], cps)
+        self.assertIn(
+            ["docker", "cp", "/host/kh", "gw:/git-gate/creds/bottle1/foo-known_hosts"], cps,
+        )
+        # The init script runs in the gateway, namespaced under the bottle id.
+        exec_scripts = [c for c in calls if c[:3] == ["docker", "exec", "gw"] and c[3] == "sh"]
+        self.assertEqual(1, len(exec_scripts))
+        self.assertIn("repo=/git/bottle1/${name}.git", exec_scripts[0][-1])
+
+    def test_omits_known_hosts_copy_when_absent(self) -> None:
+        calls: list[list[str]] = []
+        with patch(_RUN, side_effect=_recorder(calls)):
+            provision_git_gate("gw", "b1", _plan(_up("foo")))  # no known_hosts
+        cps = [c for c in calls if c[:2] == ["docker", "cp"]]
+        self.assertEqual(1, len(cps))  # only the key, not known_hosts
+        self.assertTrue(cps[0][3].endswith("/foo-key"))
+
+    def test_no_upstreams_is_noop(self) -> None:
+        with patch(_RUN) as m:
+            provision_git_gate("gw", "b1", _plan())
+        m.assert_not_called()
+
+    def test_raises_on_docker_failure(self) -> None:
+        with patch(_RUN, return_value=_proc(returncode=1, stderr="boom")):
+            with self.assertRaises(GatewayProvisionError):
+                provision_git_gate("gw", "b1", _plan(_up("foo")))
+
+    def test_rejects_unsafe_bottle_id_before_any_docker(self) -> None:
+        with patch(_RUN) as m:
+            with self.assertRaises(GatewayProvisionError):
+                provision_git_gate("gw", "../etc", _plan(_up("foo")))
+        m.assert_not_called()  # rejected before a single docker call
+
+
+class TestDeprovision(unittest.TestCase):
+    def test_removes_repo_and_creds(self) -> None:
+        with patch(_RUN, return_value=_proc()) as m:
+            deprovision_git_gate("gw", "b1")
+        argv = m.call_args.args[0]
+        self.assertEqual(["docker", "exec", "gw", "rm", "-rf"], argv[:5])
+        self.assertIn("/git/b1", argv)
+        self.assertIn("/git-gate/creds/b1", argv)
+
+    def test_rejects_unsafe_bottle_id(self) -> None:
+        with patch(_RUN) as m:
+            with self.assertRaises(GatewayProvisionError):
+                deprovision_git_gate("gw", "a/b")
+        m.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()