End-to-end testing

[tenderdeve]

Description

Comprehensive testing across all features and edge cases.

Tasks

• Test with real wallets: multi-position, tokens-only, empty, invalid address
• Test BYOK: add key → unlimited → remove → back to free
• Test free limits: 1 report → second blocked → upgrade prompt
• Test chat grounding: answers reference actual portfolio data
• Test error states: API failures → graceful degradation
• Test mobile layout: tabs work, responsive design
• Test auth: sign in → session persists → sign out → redirect

Acceptance Criteria

All test cases pass. No crashes. Errors handled. Mobile responsive.

Dependencies

Depends on: #26, #27, #28

Estimate

3-4 hours