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/provision/ca.py

@@ -1,19 +1,8 @@
-"""Install the per-bottle MITM CA into the agent container's trust
-store.
+"""Install the per-bottle egress MITM CA into the agent container's
+trust store.
 
-Post-PRD-0017 the CA depends on the agent's HTTP_PROXY target:
-
-  - Bottle declares `egress.routes[]` → agent's HTTP_PROXY
-    points at egress; the cert the agent must trust is the
-    one egress mints leaf certs with (the egress CA).
-  - No egress routes → agent's HTTP_PROXY points straight at
-    pipelock; the cert the agent must trust is pipelock's CA (the
-    pre-cutover behavior).
-
-By the time this provisioner runs, the corresponding `tls_init`
-helper has generated the chosen CA under `plan.stage_dir`, and the
-sidecar (pipelock or egress) is up referencing the
-in-container CA paths.
+By the time this provisioner runs, `egress_tls_init` has generated
+the egress CA and the path is re-bound into `plan.egress_plan`.
 
 Cert lands on Debian's standard source path
 (`/usr/local/share/ca-certificates/`); `update-ca-certificates`
@@ -40,7 +29,7 @@ def provision_ca(plan: DockerBottlePlan, bottle: Bottle) -> None:
     """Copy the agent-facing CA cert into the agent, rebuild the
     trust bundle, emit a one-line fingerprint log. Called from
     `BottleBackend.provision` after the agent container is up."""
-    cert_host_path, label = select_ca_cert(plan.egress_plan, plan.proxy_plan)
+    cert_host_path, label = select_ca_cert(plan.egress_plan)
 
     bottle.cp_in(str(cert_host_path), AGENT_CA_PATH)
     bottle.exec(