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>

bot_bottle/backend/docker/sidecar_bundle.py

@@ -2,10 +2,10 @@
 (PRD 0024).
 
 The bundle image (built by Dockerfile.sidecars, PRD 0024 chunk 1)
-runs pipelock + egress + git-gate + supervise as one container
-per bottle under a small Python init supervisor. As of chunk 5
-the bundle is the only shape — the legacy four-sidecar topology
-and its `BOT_BOTTLE_SIDECAR_BUNDLE` feature flag are gone."""
+runs egress + git-gate + supervise as one container per bottle
+under a small Python init supervisor. As of chunk 5 the bundle
+is the only shape — the legacy four-sidecar topology and its
+`BOT_BOTTLE_SIDECAR_BUNDLE` feature flag are gone."""
 
 from __future__ import annotations