Idea: template-first experimental lane promotion gate

[SproutSeeds]

I did a fresh current-main reread and a small draft PR strawman for a later-stage but still portable primitive: an experimental-lane promotion gate.

Draft PR strawman: #48

Current GPD already has strong pause/resume logic and pattern promotion. What it still does not expose is a clean artifact for deciding whether an optional tool or workflow lane should be:

• promoted
• kept experimental
• paused

The first slice stays template-first and intentionally keeps the lane decision separate from runtime settings or core execution state.

Questions I’d especially love feedback on:

1. Does this kind of bounded pilot / promotion artifact fit GPD at all?
2. If it does, should it stay strictly for optional tool/workflow lanes rather than core phase execution?
3. Is this better treated as a low-priority later surface, or does it feel useful sooner?