chore: strip pipelock from Docker backend

- Remove pipelock_state_dir, _PIPELOCK_SUBDIR from bottle_state.py
- Remove proxy_plan: PipelockProxyPlan from DockerBottlePlan
- Remove EGRESS_PIPELOCK_CA_IN_CONTAINER from docker/egress.py
- Remove pipelock TLS init and proxy_plan population from launch.py
- Remove PipelockProxy import and pipelock_dir setup from prepare.py
- Remove pipelock volumes, daemon entry, and network alias from compose.py
- Remove pipelock mirroring entirely from egress_apply.py
- Agent HTTP_PROXY now always points at egress (no pipelock fallback)

bot_bottle/backend/docker/bottle_plan.py

@@ -11,7 +11,6 @@ from dataclasses import dataclass, field
 from pathlib import Path
 
 from ...agent_provider import PromptMode
-from ...pipelock import PipelockProxyPlan
 from .. import BottlePlan
 
 
@@ -40,7 +39,6 @@ class DockerBottlePlan(BottlePlan):
     # accidental log of the plan dataclass.
     forwarded_env: dict[str, str] = field(repr=False)
     prompt_file: Path
-    proxy_plan: PipelockProxyPlan
     use_runsc: bool
 
     @property