Regenerate the v1.1 setup demo

[BrettKinny]

This was generated by AI during triage.

Type: HITL

What to build

Regenerate the tracked first-run setup animation from the current v1.1 demo source and visually verify that it represents the shipped prompts and MOTD. The source now includes Helix, the non-first default-editor prompt, current assistants, the completion banner, version display, and the help hint; the binary GIF still predates those changes.

Acceptance criteria

• Run the documented VHS recording workflow with pinned/currently documented prerequisites.
• The animation shows current AI, editor, default-editor, TUI, multiplexer, SDK, and shell choices in the same order as setup.
• The final screen includes the v1.1 version presentation and sqrbx-help hint.
• Extract and inspect representative frames from the beginning, each selection transition, and the final MOTD; text is legible at the README size.
• The generated GIF is updated with the demo source in the same change and README still references it.
• Record the VHS/ffmpeg/ttyd versions and any intentional simulation differences in this issue.

Blocked by

None - can start immediately.