refactor(skills): SDD e2e verification becomes pre-finish offer with disclosure doc

The predicate-keyed at-skill-start trigger is replaced by an unconditional
offer to the human after the final whole-branch review, before
finishing-a-development-branch. The procedure (spec discovery,
author/checker/runner flow, fix-wave rules) moves to spec-derived-e2e.md;
SKILL.md keeps the offer, a flowchart node, and the Integration reference.
Micro-tested 6/6: four controllers at the post-review point all offer
before finishing (including under wrap-up-efficiently pressure with the
human away); two accepted-offer controllers follow the disclosure doc with
the checker run by the controller, one fix subagent, and a fix-diff review
gate. Deviation recorded in the design spec.

docs/superpowers/specs/2026-07-04-spec-derived-scenario-cards-design.md

@@ -227,6 +227,17 @@ shipped form governs.
   touches, not the plan-named spec alone — plan-named-spec-only wiring
   skipped the step when the plan named no spec (GREEN iteration 1); the
   opt-out for spec-less repos is preserved.
+- **SDD integration restructured (2026-07-05, maintainer direction):** the
+  predicate-keyed at-skill-start detection in §3 is replaced by an
+  unconditional offer to the human after the final whole-branch review and
+  before finishing-a-development-branch — the human decides, not a spec
+  predicate. The procedure (spec discovery, author/checker/runner flow,
+  fix-wave rules) moved to a disclosure doc,
+  `skills/subagent-driven-development/spec-derived-e2e.md`; SKILL.md keeps
+  only the offer plus a reference, and the SDD flowchart now carries the
+  offer node (superseding §3's "flowchart is not modified"). Spec-less
+  repos surface "nothing to derive from" at offer time instead of skipping
+  silently.
 
 ## Decisions