Merge frozen lab b1666951 (Wave 3) into Wave 4 effects provenance

Integrates the merged and frozen Wave 3 lab commit
b1666951faf8285054e1ca90f11533b0fb53fb57 with a normal merge, preserving
every Wave 4 commit unchanged.

Conflict: src/agent_runtime/resources.py. Wave 3's _control_plane_snapshot()
/ _control_plane_path(path, *, snapshot=None) split is kept. The snapshot adds
the effect-store directories to its prefix set after the recursive job-dir
inventory and no longer references path (the auto-merged prefix check would
have raised NameError there). _control_plane_path calls _aliases_effect_store
after its os.stat, only for multiply linked files, so single-link files never
list the store.

Semantic reconciliation (no textual conflict): bg_monitor keeps launch
settlement right after the first successful validate_job and before the
authority check, with Wave 3's post-drain revalidation intact. The
deleted-session branch, terminal before linkage validation, now settles a
validated launch too: that job is later pruned and its publication retired,
which would otherwise leave its effect RUNNING. Regression tests cover the
snapshot form of the effect-store check and both deleted-session linkage
outcomes.

src/agent_tools/subprocess_tools.py

@@ -513,6 +513,7 @@ async def _run_owned_command(command, ctx: dict, *, tool: str, timeout: int, arg
     from src.tool_execution import agent_cwd, _truncate
 
     grant = None
+    launch = None
     result = None
     try:
         from src.agent_runtime.process_resources import require_launch, publish_launch, validate_launch_spec
@@ -554,6 +555,16 @@ async def _run_owned_command(command, ctx: dict, *, tool: str, timeout: int, arg
                 **({"failure_kind": "resource_linkage_unavailable",
                     "teardown": result.release.to_dict() if result.release else {"dead": False}}
                    if result is not None else {})}
+    finally:
+        if launch is not None and grant is not None:
+            record = containment._load_records().get(grant.id, {})
+            if (record.get("launch_generation") == launch.generation
+                    and (record.get("release") or {}).get("dead") is True):
+                from src.agent_runtime.process_resources import retire_launch
+                try:
+                    retire_launch(launch, grant.id)
+                except (OSError, ValueError, TypeError):
+                    logger.warning("Foreground launch publication retirement failed", exc_info=True)
 
     boundary = result.grant.to_dict()
     boundary["executed"] = True