* feat(quick-dev): sync sprint-status.yaml on epic-story implementation
When quick-dev infers the intent is an epic story, resolve the full
sprint-status key during step-01's previous-story-continuity sub-step,
then sync sprint-status.yaml at the two workflow boundaries code-review
already owns the trailing half of:
- step-03 start: flip the story to in-progress and lift the parent
epic out of backlog if needed.
- step-05 end: flip the story to review. Code-review keeps ownership
of review -> done.
Resolution uses exact numeric-segment equality on the {epic}-{story}
prefix (never string-prefix match), so 1-1 no longer collides with
1-10. Both sync blocks are idempotent so step-04 loopbacks do not
clobber human edits or bump last_updated without cause. Skips silently
when sprint-status.yaml is missing or the intent is not an epic story.
* feat(quick-dev): add sprint-status sync to one-shot route
Epic stories do get implemented via one-shot in practice. Add the same
in-progress / review sync pair that step-03 and step-05 already have,
with identical idempotency guards and skip-on-missing behavior.
* refactor(quick-dev): extract sprint-status sync into shared file
Replace inline sync blocks in step-03, step-05, and step-oneshot with
one-line callouts to sync-sprint-status.md. The shared file owns all
edge-case handling (idempotency, epic lift, missing file/key) and is
parameterized by {target_status}. Any future route picks it up with a
single Follow line.
* fix(quick-dev): resolve story_key on early-exit resume paths
Extract story-key resolution into a shared subsection referenced by
all early-exit paths and INSTRUCTIONS, ensuring sprint-status sync
works for resumed epic stories.
* refactor(quick-dev): tighten story-key resolution prompt
Remove mechanical details the LLM can infer; keep only the
collision-prevention constraint.