persistency enhancement points to dicuss

### What

i want to discuss the follwoing enhancement points for score-persistency :

- CRUD-APIS : remove_all_keys()
- CRUD-APIS : Discard_pending_changes()
- CRUD-APIS : Get_Storage_file_size()
- Redundancy : KVS_MAX_SNAPSHOT is fixed number
- Corruption : using CRC64 instead of Adler32
- backup : create backup file before open storage file , all backup files deleted before open function called.
- Cleanup persistency : API to remove backup files.
- concurrent Process access : need to be documented if it is possible or not ?? Should be not :) --> should be existing feature requirmenent
- storage access control (Permissions )
- Configuration json file (and priorization, assumption file config overwrites "code config")
- get_value api not return default value , if default value is needed there are another API to get default value.
--> 2026-08-20: Discussed in FT meeting: Working assumption ... no implicit fallback to default app needs to explicit request if wanted
- support encrypted storage files

### Acceptance Criteria (DoD)

take decision for each point .

### How

_No response_