Error handling

[Joel-Joseph-George]

Context

• Part of the mobile sync epic: Mobile API integration & initial data sync #14
• Can run in parallel with Fetch & upsert all API data #16, Sync trigger + MMKV state #17 , Inline sync status UI #18

Background

Each sync step should fail independently — a single failing step should
not crash or block the rest of the sync sequence. Errors are stored in
MMKV per step and surfaced inline on the home screen.

Tasks

Per-step error handling

• Wrap each API call individually in try/catch
• On network error or non-2xx response, store the error in MMKV:
  sync_error_<step> with the error message string
• Do not throw or bubble up — let the next step continue

Step keys

MMKV key	Step
sync_error_projects	GET /users/:userId/projects
sync_error_chapter_assignments	GET /users/:userId/chapter-assignments
sync_error_project_units	Deriving project_units
sync_error_bible_texts	POST /bibles/:bibleId/bulk-texts

Acceptance criteria

• A failing step does not crash or block subsequent steps
• Each failed step writes its error message to the correct
  sync_error_<step> key in MMKV
• Errors are visible inline on the home screen per step
  (handled by #XX Inline sync status UI)
• No global error toast is shown

[B3RN153]

1. Research (Et -2hrs)
2. Implementations (ET-5hrs)