spiffy-carryover

name	spiffy-carryover
description	Carry shared or u64-specific 1541ultimate changes into Spiffy c64u while preserving Spiffy-only behavior such as WASD differences.

Intent

Use this skill when asked to onboard 1541ultimate u64 changes into c64u, sync Spiffy from 1541ultimate, or merge authored u64 carryover work without losing existing Spiffy behavior.

Workflow model: inventory -> compare -> merge -> validate, always ending with the patched outcome in patches/spiffy-ultimate.

Inputs

• The upstream 1541ultimate commit range, files, or feature area to carry over.
• The current Spiffy target area under work/spiffy-ultimate or patches/spiffy-ultimate.
• The validation target, normally c64u.

Execution

1. Identify the exact 1541ultimate source changes that should move into Spiffy.
2. Compare those changes against the current Spiffy source and any existing patch overlay before editing.
3. Treat Spiffy-only behavior as authoritative local intent unless the user explicitly asked to drop it.
4. When 1541ultimate and Spiffy both changed the same area, merge them deliberately instead of copying one side over the other.
5. Preserve Spiffy-only deltas such as the existing WASD-related c64u behavior while bringing over compatible 1541ultimate improvements.
6. In the USB HID keyboard path, preserve Spiffy's boot-keyboard preference for boot-capable keyboards unless you have validated a replacement on real c64u hardware; a report-protocol-first carryover can leave normal keys dead while special combinations such as CBM+Restore still appear to work.
7. Write the merged outcome into patches/spiffy-ultimate, not upstream/.
8. Re-run the smallest relevant ./forge build ... validation, then transiently run on c64u when the task requires device validation.

Validation

1. Confirm the final merged file or files live under patches/spiffy-ultimate.
2. State which Spiffy-only deltas were preserved during the merge.
3. When the carryover touched USB HID input, explicitly confirm whether the boot-keyboard preference was preserved or intentionally replaced.
4. Report the exact ./forge build c64u and ./forge run c64u results when the carryover touched runtime behavior.

Safety

• Never replace a Spiffy file wholesale with 1541ultimate content until you have checked for Spiffy-only deltas.
• Do not lose c64u-side behavior that is absent upstream, including known WASD-related menu and input changes, unless the user explicitly asks for that regression.
• Treat any HID change that leaves only CBM+Restore working as a keyboard regression, not a partial success.
• Do not edit upstream/; keep the shareable merged result in patches/spiffy-ultimate.