Implement Solution A (complete deferred submission) for custom endpoint
management, replacing the dual-mode system with unified local staging.
Changes:
- Remove immediate backend saves from EndpointSpeedTest
* handleAddEndpoint: local state update only
* handleRemoveEndpoint: local state update only
* handleSelect: remove lastUsed timestamp update
- Add explicit clear detection in ProviderForm
* Distinguish "user cleared endpoints" from "user didn't modify"
* Pass empty object {} as clear signal vs null for no-change
- Fix mergeProviderMeta to handle three distinct cases:
* null/undefined: don't modify endpoints (no meta sent)
* empty object {}: explicitly clear endpoints (send empty meta)
* with data: add/update endpoints (overwrite)
Fixed Critical Bug:
When users deleted all custom endpoints, changes were not saved because:
- draftCustomEndpoints=[] resulted in customEndpointsToSave=null
- mergeProviderMeta(meta, null) returned undefined
- Backend interpreted missing meta as "don't modify", preserving old values
Solution:
Detect when user had endpoints and cleared them (hadEndpoints && length===0),
then pass empty object to mergeProviderMeta as explicit clear signal.
Architecture Improvements:
- Transaction atomicity: all fields submitted together on form save
- UX consistency: add/edit modes behave identically
- Cancel button: true rollback with no immediate saves
- Code simplification: removed ~40 lines of immediate save error handling
Testing:
- TypeScript type check: passed
- Rust backend tests: 10/10 passed
- Build: successful