Workspace persistence is fragile on localStorage; move graph/session storage to IndexedDB with migration + recovery

[avinxshKD]

We currently autosave full graph payloads into localStorage. This is brittle for larger workflows and can silently drop history when storage writes fail. Session restore is also partial (open tabs/active tab/file metadata are not reliably recovered).

I’d like to move persistence persistence to IndexedDB as the primary store for graph snapshots and workspace session state, with a one-time migration from existing localStorage data.

Scope,

• add a storage layer for graphs/session/meta (versioned schema)
• migrate old localStorage entries on first run
• wire autosave/load to new storage
• keep app usable if one entry is corrupted (skip bad record, continue)
• keep fallback behavior sane when IndexedDB is unavailable
• stop silent history loss behavior during normal saves
• add automated tests for migration, session restore, corrupted-record skip, and IndexedDB-unavailable fallback
• add docs for storage schema, migration flow, fallback behavior, and manual verification steps

Acceptance criteria,

• reload restores previously open graphs + active tab
• large graphs save/load reliably without quota-related loss
• existing users are migrated automatically
• corrupted single record does not block full workspace load

[avinxshKD]

Hey @pradeeban what do you think about adding this? It should make saves more reliable for bigger workflows and stop the random session/history loss we still see with localStorage.

[pradeeban]

Fair points about the local storage. But then the counter point is, often filesystem is better than database to store binary data. If you are thinking of indexing and retrieval, perhaps a hybrid approach of storage of the files in the local file system and the metadata in a database could be the winner approach.

[avinxshKD]

@pradeeban Thanks, that makes sense. I agree with the hybrid direction. We can keep filesystem storage for files/binary exports, and use IndexedDB for autosave/session metadata + recovery (graph state, history, open tabs, active tab). That should fix the localStorage reliability issues without moving binaries into DB. If you’re aligned with this scope, I’ll update the issue and start implementation :p