feat(db_store): decouple migration from store construction

Remove auto-migration from DbStore.__init__; add explicit check_migrations()
and migrate() methods. The CLI now checks both stores on every startup and
prompts the user to confirm before migrating. supervise.prepare() calls
.migrate() directly now that __init__ no longer does it implicitly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bot_bottle/cli/__init__.py

@@ -7,8 +7,11 @@ from __future__ import annotations
 
 import sys
 
+from ..audit_store import AuditStore
+from ..db_store import DbVersionError
 from ..log import Die, die, error
 from ..manifest import ManifestError
+from ..queue_store import QueueStore
 from ._common import PROG
 from . import list as _list_mod
 from .cleanup import cmd_cleanup
@@ -74,6 +77,21 @@ def main(argv: list[str] | None = None) -> int:
     if handler is None:
         usage()
         die(f"unknown command: {command}")
+    queue_store = QueueStore("")
+    audit_store = AuditStore()
+    if not queue_store.check_migrations() or not audit_store.check_migrations():
+        sys.stderr.write("bot-bottle: database schema is out of date\n")
+        sys.stderr.write("Migrate now? [y/N] ")
+        sys.stderr.flush()
+        try:
+            answer = sys.stdin.readline().strip().lower()
+        except EOFError:
+            answer = ""
+        if answer != "y":
+            error("migration required — re-run and confirm to migrate")
+            return 1
+        queue_store.migrate()
+        audit_store.migrate()
     try:
         return handler(rest) or 0
     except ManifestError as e: