fix(issue-10,13): check every agy artifact for holders and purge orphaned leftovers

Round-3 review of f5a6575 (planner-reviewer-codex-01, R1/R2).

R1 - the adapter's in-use check handed only the conversation DB to lsof, so a
holder that keeps the presence lock (or a sidecar) open while naming the uuid
on no command line and in no session variable was invisible, and the held
lock was unlinked from under it. AgyAgentAdapter.conversation_in_use now
passes every path of the conversation (DB, -wal/-shm/-journal, brain,
annotation, presence lock).

R2 - both resolver stages required the DB, so once an interrupted or pre-#10
purge had removed it, the WAL/annotation/lock left behind were "no artifact"
(exit 5) forever. BaseAgentAdapter.has_artifacts (default: a uuid-bearing
artifact path that exists) replaces the resolver's path fallback, and agy's
override accepts any of its pieces.

Tests: a flock holder that names the uuid nowhere is refused and nothing is
removed; orphaned leftovers resolve to agy and are purged. VERSIONS.md
v4.4.3 items 1-2 and orc-onboard SKILL.md updated.

Refs #10 #13

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff

.agents/skills/lib_py/agents/__main__.py

@@ -13,8 +13,9 @@ def _resolve_purge_target(agent_hint: str, uuid: str, workspace: str):
 
     An explicit agent is trusted as long as its artifact exists. `auto` tries
     each adapter's own verification first (revalidate mode: an orchestrator
-    conversation is not in any workspace cache), then a plain path check for
-    adapters whose artifact path embeds the uuid.
+    conversation is not in any workspace cache), then the adapter's own
+    `has_artifacts` - which, for agy, also accepts orphaned sidecars, the
+    annotation or the presence lock left behind after the DB is gone.
     """
     from lib_py.agents.base import DiscoveryContext
     names = [agent_hint] if agent_hint and agent_hint != 'auto' else list(PURGE_PROBE_ORDER)
@@ -32,11 +33,10 @@ def _resolve_purge_target(agent_hint: str, uuid: str, workspace: str):
             pass
     for name, adapter, ctx in probes:
         try:
-            path = adapter.artifact_path(uuid, ctx)
+            if adapter.has_artifacts(uuid, ctx):
+                return name, adapter, ctx
         except Exception:
             continue
-        if uuid in path and os.path.exists(path):
-            return name, adapter, ctx
     return None