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/migrations.py

@@ -0,0 +1,37 @@
+"""SQLite migration runner for bot-bottle stores."""
+
+from __future__ import annotations
+
+import sqlite3
+
+
+class TableMigrations:
+    """Runs a sequential list of DDL migrations tracked by schema_key in schema_versions."""
+
+    def __init__(self, schema_key: str, migrations: list[str]) -> None:
+        self.schema_key = schema_key
+        self.migrations = migrations
+
+    def apply(self, conn: sqlite3.Connection) -> None:
+        conn.execute(
+            """
+            CREATE TABLE IF NOT EXISTS schema_versions (
+                module TEXT PRIMARY KEY,
+                version INTEGER NOT NULL DEFAULT 0
+            )
+            """
+        )
+        row = conn.execute(
+            "SELECT version FROM schema_versions WHERE module = ?",
+            (self.schema_key,),
+        ).fetchone()
+        version = row[0] if row else 0
+        for i, sql in enumerate(self.migrations[version:], start=version + 1):
+            conn.execute(sql)
+            conn.execute(
+                "INSERT OR REPLACE INTO schema_versions (module, version) VALUES (?, ?)",
+                (self.schema_key, i),
+            )
+
+
+__all__ = ["TableMigrations"]