test: cover QueueStore/AuditStore guard branches and supervise bundle spec

Add 8 tests covering the branches that were keeping diff-coverage below
90%: explicit db_path constructor arg, early-return guards when the DB
file is absent, _chmod OSError swallowing in both store classes, and the
supervise volume/env/daemon path in _bundle_launch_spec.

Diff-coverage rises from 89.2% to 94.6% (176/186 changed lines).

tests/unit/test_smolmachines_provision.py

@@ -422,6 +422,14 @@ class TestBundleLaunchSpec(unittest.TestCase):
             spec.environment,
         )
 
+    def test_supervise_adds_daemon_volume_and_env(self):
+        from bot_bottle.supervise import DB_PATH_IN_CONTAINER
+        plan = _plan(supervise=True)
+        spec = _bundle_launch_spec(plan, "net", "127.0.0.16")
+        self.assertIn("supervise", spec.daemons_csv)
+        self.assertIn(f"SUPERVISE_DB_PATH={DB_PATH_IN_CONTAINER}", spec.environment)
+        self.assertIn(("/tmp/bot-bottle.db", DB_PATH_IN_CONTAINER, False), spec.volumes)
+
     def test_canary_env_visible_to_smolvm_guest(self):
         plan = _plan(canary=True)
         with patch.object(

tests/unit/test_supervise_edge.py

@@ -7,9 +7,12 @@ from __future__ import annotations
 import tempfile
 import time
 import unittest
+from pathlib import Path
 from unittest.mock import patch
 
 from bot_bottle import supervise
+from bot_bottle.audit_store import AuditStore
+from bot_bottle.queue_store import QueueStore
 from bot_bottle.supervise import (
     AuditEntry,
     Proposal,
@@ -132,5 +135,56 @@ class TestReadAuditEntries(unittest.TestCase):
             self.assertEqual([], entries)
 
 
+class TestStoreGuardBranches(unittest.TestCase):
+    """Direct QueueStore / AuditStore construction and early-return guard branches."""
+
+    def test_queue_store_explicit_db_path(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "q.db"
+            store = QueueStore("key", db_path=db)
+            self.assertTrue(db.is_file())
+            self.assertEqual(db, store.db_path)
+
+    def test_queue_store_missing_db_list_pending_returns_empty(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "q.db"
+            store = QueueStore("key", db_path=db)
+            db.unlink()
+            self.assertEqual([], store.list_pending_proposals())
+
+    def test_queue_store_missing_db_list_all_returns_empty(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "q.db"
+            store = QueueStore("key", db_path=db)
+            db.unlink()
+            self.assertEqual([], store.list_all_pending_proposals())
+
+    def test_queue_store_missing_db_archive_is_noop(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "q.db"
+            store = QueueStore("key", db_path=db)
+            db.unlink()
+            store.archive_proposal("anything")  # must not raise
+
+    def test_queue_store_chmod_oserror_is_swallowed(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "q.db"
+            with patch("pathlib.Path.chmod", side_effect=OSError("ro")):
+                QueueStore("key", db_path=db)  # must not raise
+
+    def test_audit_store_missing_db_read_returns_empty(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "a.db"
+            store = AuditStore(db_path=db)
+            db.unlink()
+            self.assertEqual([], store.read_audit_entries("egress", "slug"))
+
+    def test_audit_store_chmod_oserror_is_swallowed(self):
+        with tempfile.TemporaryDirectory() as d:
+            db = Path(d) / "a.db"
+            with patch("pathlib.Path.chmod", side_effect=OSError("ro")):
+                AuditStore(db_path=db)  # must not raise
+
+
 if __name__ == "__main__":
     unittest.main()