The migration path must prefer the current legacy JSON source over older per-account vault leftovers, clean those leftovers after a valid manifest is available, and avoid write operations overwriting a damaged or unreadable vault payload with fallback defaults.
Constraint: credentials.json is migration-only, but it was the previous Tauri source of truth.\nRejected: Use read fallback for mutating updates | can overwrite unreadable vault data with defaults.\nConfidence: high\nScope-risk: narrow\nDirective: Mutating credential operations must propagate chunked vault read errors instead of saving fallback roots.\nTested: cargo check --manifest-path src-tauri/Cargo.toml\nTested: cargo test --manifest-path src-tauri/Cargo.toml credential_payload_chunks_stay_under_windows_blob_limit\nTested: npm run -s build\nTested: git diff --check\nNot-tested: Manual migration with simultaneous JSON and stale per-account vault entries.\nRelated: #230
H-Chris233
9a1461bcb6