Migration Plan: @push.rocks/smartrequest

To re-read CLAUDE.md: cat ~/.claude/CLAUDE.md

Objective

Migrate the Bunq HTTP client from native fetch to @push.rocks/smartrequest to leverage built-in rate limiting, better error handling, and improved maintainability.

Tasks

1. Setup

• [x] Install @push.rocks/smartrequest dependency using pnpm
• [x] Update ts/bunq.plugins.ts to import smartrequest

2. Refactor BunqHttpClient

• [x] Replace fetch-based makeRequest method with SmartRequest implementation
• [x] Preserve all custom headers (X-Bunq-*)
• [x] Maintain request signing functionality
• [x] Keep response signature verification
• [x] Map LIST method to GET (SmartRequest doesn't have LIST)
• [x] Replace manual retry logic with built-in handle429Backoff()

3. Error Handling

• [x] Ensure BunqApiError is still thrown for API errors
• [x] Map SmartRequest errors to appropriate error messages
• [x] Preserve error message format for backward compatibility

4. Testing

• [x] Run existing tests to ensure no regression (tests passing)
• [x] Verify rate limiting behavior works correctly
• [x] Test signature creation and verification
• [x] Ensure all HTTP methods (GET, POST, PUT, DELETE, LIST) work

5. Cleanup

• [x] Remove unused code from the old implementation (manual retry logic removed)
• [x] Update any relevant documentation or comments

Implementation Notes

Key Changes

1. Replace native fetch with SmartRequest fluent API
2. Use built-in handle429Backoff() instead of manual retry logic
3. Leverage SmartRequest's response methods (.json(), .text())
4. Maintain all Bunq-specific behavior (signatures, custom headers)

Risk Mitigation

• All Bunq-specific logic remains unchanged
• Public API of BunqHttpClient stays the same
• Error handling maintains same format