Testing: Create and execute manual testing checklist

[UncleTallest]

Goal: Comprehensive manual testing before v0.1 release.

Tasks:

• Create testing checklist document
• Test on Ubuntu (GNOME/Wayland)
• Test on Fedora (GNOME/Wayland)
• Test on Arch (GNOME/Wayland)
• Verify all success criteria from roadmap
• Test error cases (no network, invalid token, etc.)
• Performance testing (large conversations)
• Document any bugs found

Success criteria:

• All MVP features work as expected
• No critical bugs
• Performance acceptable on mid-range hardware

Output: docs/testing/v0.1-manual-test-checklist.md