fix(DE-085): apply scope-delta skill update to source, not just installed copy

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: davidlee

supekku/skills/scope-delta/SKILL.md

@@ -19,6 +19,11 @@ Process:
      - `uv run spec-driver create delta "<title>" --spec SPEC-XXX --requirement SPEC-XXX.FR-001`
    - From backlog item:
      - `uv run spec-driver create delta --from-backlog ISSUE-XXX`
+     - `--from-backlog` auto-populates `context_inputs` and `relations` from the source item.
+   - When creating a delta motivated by a backlog item (even without `--from-backlog`), ensure:
+     - `context_inputs` includes `type: issue` (or appropriate type) with the backlog item ID
+     - `relations` includes `type: relates_to` (or more specific type) with the backlog item ID as target
+     - `applies_to.requirements` includes any requirement IDs from the backlog item
 4. Ensure delivery bundle is present and usable:
    - `DE-XXX.md`
    - `DR-XXX.md` (if non-trivial change)