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_supervise_server.py

@@ -47,28 +47,6 @@ from bot_bottle.supervise_server import (
 
 
 class TestValidation(unittest.TestCase):
-    def test_pipelock_block_accepts_https_url(self):
-        validate_proposed_file(
-            _sv.TOOL_PIPELOCK_BLOCK,
-            "https://api.github.com/repos/foo/bar",
-        )
-
-    def test_pipelock_block_accepts_http_url(self):
-        validate_proposed_file(
-            _sv.TOOL_PIPELOCK_BLOCK,
-            "http://internal.example/path/to/thing",
-        )
-
-    def test_pipelock_block_rejects_missing_scheme(self):
-        with self.assertRaises(_RpcError) as cm:
-            validate_proposed_file(_sv.TOOL_PIPELOCK_BLOCK, "api.github.com/foo")
-        self.assertIn("http://", str(cm.exception.message))
-
-    def test_pipelock_block_rejects_missing_host(self):
-        with self.assertRaises(_RpcError) as cm:
-            validate_proposed_file(_sv.TOOL_PIPELOCK_BLOCK, "https:///just-a-path")
-        self.assertIn("hostname", str(cm.exception.message))
-
     def test_capability_block_accepts_anything_nonempty(self):
         validate_proposed_file(
             _sv.TOOL_CAPABILITY_BLOCK,