Establish the LUT-building workflow hierarchy

[Today20092]

Parent

• Redesign the LUT Builder workflow and interface #23

What to build

Reshape the existing single-page LUT Builder into a clear, responsive workflow where camera/display configuration establishes context before a dominant exposure-band workspace, encoded-signal warnings follow editing, and LUT generation is the final primary action. Preserve all current configuration, preview, import/export, and generation behavior.

Acceptance criteria

• Camera profile, target display, cube size, band mode, monochrome base, legal/video range, and output filename are presented before the exposure-band editor in the page's reading and keyboard order.
• The exposure-band workspace remains full width and is visually more prominent than supporting configuration and warning sections.
• Encoded-signal warning controls appear after exposure-band editing and before the final generation action.
• LUT generation is the single primary page action; import and configuration export remain available as secondary actions.
• The generation label identifies the configured camera-to-display transformation when space permits.
• Progress, success, validation, and failure feedback is associated with the final action area and remains announced to assistive technology.
• At narrow widths, controls stack without clipping, horizontal page scrolling, or a changed workflow order.
• Existing preview, import, export, and generation API behavior remains unchanged.
• Existing automated tests and the frontend production build pass.
• The result is manually verified at desktop and narrow viewport widths.

Blocked by

None ? can start immediately.