fix(tests): wrap message arrays with conversion functions

Update all E2E tests to explicitly use fromChatMessages() and fromClaudeMessages()
conversion functions instead of passing raw message arrays directly.

This fixes CI validation failures caused by removal of automatic message format
conversion. Now all tests properly demonstrate the required usage pattern:
- Chat-style messages → fromChatMessages()
- Claude-style messages → fromClaudeMessages()

Changes:
- Add imports for fromChatMessages and fromClaudeMessages
- Update ~35 test cases to wrap message arrays in conversion functions
- Fix syntax error (trailing comma) from bulk replacement

Fixes validation errors: "Invalid input: expected string, received array"

Author: mattapperson