Firstboot selection UI: 2009-2010 console theme

[Deadbytes101]

RIGOS firstboot currently uses whiptail on Linux tty1. Improve the selection experience without introducing X11, Wayland, Electron, browser UI, or a new graphics stack.

Design target

• late-2000s / early-2010s firmware and installer aesthetic
• deep blue background
• silver/blue panels
• bright selected row
• compact uppercase section labels
• visible keyboard hints
• RIGOS ASCII identity/header
• readable on 80x25 and larger consoles
• no Unicode dependency required for borders or controls

Implementation constraints

• keep the existing whiptail workflow and return-code semantics
• preserve tty1 release behavior and firstboot status journaling
• use deterministic NEWT_COLORS styling
• keep secrets out of titles, headers, and public summaries
• no persistent-state format change
• no miner, MSR, SSH, runtime-render, or config-engine behavior change
• no new runtime package unless proven necessary
• source and built-image verification must assert the theme wiring

Initial implementation branch

ui/firstboot-2009-theme

The branch starts at exact performance head 527fdbdc49f7b94b26aab2c2386463d261672cf4 so the ongoing 24-hour physical soak remains untouched on performance/randomx-sustained-hash.

Acceptance

• all firstboot dialogs inherit the theme
• Flight Sheet and identity selection screens receive improved titles/instructions
• terminal reset is guaranteed on success, cancel, signal, and failure
• existing firstboot and full source gates pass
• exact image confirms theme bytes and no added GUI stack
• UI work remains separate from PR RandomX sustained-hash performance authority #15 until the performance authority is complete