refactor(store): consolidate the SQLite store family into bot_bottle.store

Move the DbStore base (db_store), the shared schema-migration base (migrations /
TableMigrations), the concrete stores (audit_store, config_store, queue_store),
and StoreManager out of the package root into a bot_bottle/store/ package, so
persistence lives in one place rather than scattered across the root.

Callers use direct submodule imports (from bot_bottle.store.store_manager
import StoreManager). Inside the moved modules the relative imports point back
up to their non-store siblings (..paths, ..supervise_types) while co-moved
siblings stay package-local; the flat-import fallbacks are untouched. The
orchestrator's own stores (config_store, secret_store, registry) stay in
orchestrator/ and repoint to the moved DbStore / TableMigrations.

No behavior change; full unit suite green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

bot_bottle/store/__init__.py

@@ -0,0 +1,9 @@
+"""SQLite-backed persistence for bot-bottle.
+
+The store family: a shared `DbStore` base (versioned `migrations`) and the
+concrete stores built on it — `ConfigStore`, `AuditStore`, `QueueStore` — plus
+`StoreManager`, which migrates them together against the one per-host DB.
+
+Callers import the concrete module they need directly, e.g.
+`from bot_bottle.store.store_manager import StoreManager`.
+"""