feat(api): rebook reviews into a 30-day interview sprint after the break

Review 4 closes out today (Nov 2); Reviews 7-20 move to Mon/Tue/Thu/Fri from
Fri Nov 6 to Tue Dec 1 (Thanksgiving unbooked), then two sweep days and a
gate: [] Saturday that makes Dec 5 day 30. The digest counts the sprint
(SPRINT_START, length derived from the plan's end) and counts down before it.
REVIEW_CAP 3 -> 5 so the ~110-review backlog drains inside the sprint.

README.md

@@ -9,7 +9,7 @@
 </p>
 
 <p align="center">
-  <sub>Interview-prep fight camp: eight weeks of topics, then a review phase to Nov 3. Each phase is a milestone; each topic an issue; each problem a sub-issue.<br>
+  <sub>Interview-prep fight camp: eight weeks of topics, a review phase, then a 30-day interview sprint to Dec 5. Each phase is a milestone; each topic an issue; each problem a sub-issue.<br>
   New topic Mon–Fri, gate on Saturday, Sunday off — every solve comes back at <strong>+3</strong> and <strong>+7</strong> days,
   the two windows that keep the rest day clear (a Thursday solve's +3 slides to Monday).<br>
   Charts are live from the SRS Worker, never committed: pushing a solution or tapping the daily digest moves them within ~5 min.</sub>