fix: clarify dev auto sprint sync

src/bmm-skills/4-implementation/bmad-dev-auto/sync-sprint-status.md

@@ -1,18 +1,18 @@
 # Sync Sprint Status
 
-Shared sub-step for updating `sprint-status.yaml` during bmad-dev-auto. Called with a `{target_status}` parameter.
+Updates `sprint-status.yaml` for the current `{story_key}` using `{target_status}`.
 
 ## Preconditions
 
-Skip this entire file (return to caller) if ANY of:
+Stop executing this file if ANY of:
 - `{story_key}` is unset
 - `{sprint_status}` does not exist on disk
 
 ## Instructions
 
 1. Load the FULL `{sprint_status}` file.
-2. Find the `development_status` entry matching `{story_key}`. If not found, warn the user once (`"{story_key} not found in sprint-status; skipping sprint sync"`) and return to caller.
-3. **Idempotency check.** If `development_status[{story_key}]` is already at `{target_status}` or a later state (`review` is later than `in-progress`; `done` is later than both), return to caller — no write needed. Never regress a story's status.
+2. Find the `development_status` entry matching `{story_key}`. If not found, add `sprint-sync-skipped` to `{spec_file}` frontmatter `warnings` and stop executing this file.
+3. **Idempotency check.** If `development_status[{story_key}]` is already at `{target_status}` or a later state (`review` is later than `in-progress`; `done` is later than both), stop executing this file — no write needed. Never regress a story's status.
 4. Set `development_status[{story_key}]` to `{target_status}`.
 5. **Epic lift (only when `{target_status}` = `in-progress`).** Derive the parent epic key as `epic-{N}` from the leading numeric segment of `{story_key}` (e.g., `3-2-digest-delivery` → `epic-3`). If that entry exists and is `backlog`, set it to `in-progress`. Leave it alone otherwise. Skip this sub-step entirely when `{target_status}` is not `in-progress`.
 6. Refresh `last_updated` to the current date.