feat: add ledger backup safety workflow

confirm dcy-002 and add REQ/BAT evidence

add ledger backup/status metadata workflow

document restore as runbook/script-only guarded operation

add synthetic DB backup/restore smoke tests

jarca_ledger_mcp/server.py

@@ -14,6 +14,26 @@ def ledger_health_check() -> dict:
     """Verify the Jarca Ledger MCP server and SQLite database are reachable."""
     return service.health_check()
 
+@mcp.tool()
+def get_ledger_db_status(include_hash: bool = True, include_integrity: bool = True) -> dict:
+    """Return non-sensitive DB status evidence: path, size, mtime, checksum, table row counts, and aggregate totals."""
+    return service.get_ledger_db_status(include_hash=include_hash, include_integrity=include_integrity)
+
+@mcp.tool()
+def create_ledger_backup(backup_dir: str = "", retention_days: int = 30, retention_count: int = 20) -> dict:
+    """Create a timestamped ledger DB backup. Restore is intentionally not exposed as an MCP tool."""
+    return service.create_ledger_backup(backup_dir=backup_dir or None, retention_days=retention_days, retention_count=retention_count)
+
+@mcp.tool()
+def list_ledger_backups(backup_dir: str = "", include_hash: bool = False, limit: int = 50) -> dict:
+    """List ledger DB backups with metadata-only evidence."""
+    return service.list_ledger_backups(backup_dir=backup_dir or None, include_hash=include_hash, limit=limit)
+
+@mcp.tool()
+def get_ledger_backup_status(file_path: str, include_hash: bool = True, include_integrity: bool = True) -> dict:
+    """Return metadata-only status and integrity evidence for one backup file."""
+    return service.get_ledger_backup_status(file_path, include_hash=include_hash, include_integrity=include_integrity)
+
 @mcp.tool()
 def create_ledger_account(name: str, type: str = "bank", institution: str = "", currency: str = "KRW", active: bool = True, memo: str = "", account_number_masked: str = "", holder_name: str = "", last_balance: int | None = None, last_synced_at: str = "") -> dict:
     """Create an account/card/cash/investment/loan ledger account."""