chore: remove all pipelock references from tests, docs, and non-pipelock source

- Strip pipelock from all unit and integration test fixtures:
  proxy_plan fields removed from DockerBottlePlan/SmolmachinesBottlePlan
  constructors; pipelock-specific test classes deleted or renamed
- Update test_sidecar_init: remove test_pipelock_loses_egress_tokens,
  rename "pipelock" daemon fixtures to "git-gate" throughout
- Remove test_pipelock_binary_present_and_versioned from integration test
- Remove test_pipelock_answers_on_bundle_ip from smolmachines launch test
- Update _SANDBOX_BLOCK_MARKERS: remove "pipelock" marker (egress blocks)
- Dockerfile.sidecars: remove pipelock build stage and COPY; update layout
  comments and port table
- egress_entrypoint.sh: update comments now that egress is sole proxy
- Clean up pipelock references in comments/docstrings across backend,
  network, manifest, supervise, git_gate, yaml_subset, agent_provider,
  sidecar_bundle, sidecar_init, egress_addon_core modules

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/test_docker_launch_teardown.py

@@ -22,7 +22,6 @@ from bot_bottle.backend.docker.bottle_plan import DockerBottlePlan
 from bot_bottle.egress import EgressPlan
 from bot_bottle.git_gate import GitGatePlan
 from bot_bottle.manifest import Manifest
-from bot_bottle.pipelock import PipelockProxyPlan
 from bot_bottle.workspace import workspace_plan
 
 
@@ -80,10 +79,6 @@ def _plan(tmp: str) -> DockerBottlePlan:
         env_file=stage / "env",
         forwarded_env={},
         prompt_file=stage / "prompt.txt",
-        proxy_plan=PipelockProxyPlan(
-            yaml_path=stage / "pipelock.yaml",
-            slug="test-teardown-00001",
-        ),
         use_runsc=False,
     )
 
@@ -101,10 +96,6 @@ class TestTeardownWarning(unittest.TestCase):
         buf = io.StringIO()
 
         with mock.patch.object(launch_mod.docker_mod, "build_image"), \
-             mock.patch.object(
-                 launch_mod, "pipelock_tls_init",
-                 return_value=(Path("/ca.crt"), Path("/ca.key")),
-             ), \
              mock.patch.object(
                  launch_mod, "egress_tls_init",
                  return_value=(Path("/egress_ca"), Path("/egress_cert")),