Prototype Sapho first after completed movement turns

Allow a physical Sapho holder to go first among remaining unstarted combined
shipment/movement turns after earlier players have fully finished. Preserve
completed resources, cards, counters and physical order. Keep Advanced Guild
priority guarded until Guild leaves the remaining queue. Reuse private controls,
all four AI profiles and the existing action/CAS continuation.

Add four engine regressions and one independently authored SQLite recovery race;
upgrade the existing Sapho Advanced engine fixture to genuine Advanced setup.
Update player guidance and the rules decision register. Record the fourteen
Leader Skill cards and lifecycle as sourced future work, with unresolved edges.
No mode or publication gates are opened.

Validation: check (types, lint, 4,369 offline tests) and build passed. All 35 focused
Sapho tests passed; independent engine/persistence review found no blocker.
One initial focused Advanced test omitted the existing Guild shipment approval;
it was corrected to resolve that real decision before ending the turn.
No HTTP/auth/schema change; the HTTP suite was not repeated for this checkpoint.

Following the reported power outage, the existing localhost server was healthy,
SQLite integrity/foreign-key checks passed, and the saved QA seat restored the
same private hand, forces, resources and pending Storm decision after refresh.
All 291 opening room versions/state hashes and all application seat/recovery/
entry/handover records match the fresh backup. Cloudflare internal metadata
changed; application data did not. No restart or database reset was needed.

Source fingerprint: de0e0e52ef7b6888792a6e2ec5e8c4745da446ece843bf3092320e915d621266
Private report: /home/quintine/.local/share/dune/checkpoints/20260913-sapho-completed-boundary-checks/report.json
Private backup/comparison: /home/quintine/.local/share/dune/checkpoints/20260913-outage-sapho-before/
Check duration 146645 ms; build 6753 ms. Reported aggregate goal counter at this
milestone opening was 65037986 and before Git was 65524147 (486161 difference,
including outage recovery, parallel source research and coordination; not a
billing measurement or a savings claim).

docs/IMPLEMENTATION_STATUS.md

@@ -1,5 +1,31 @@
 # Dune implementation status
 
+## 13 September 2026 — Sapho first after completed movement turns
+
+Extends the existing clean-boundary movement contract to let Sapho's holder
+act first among remaining unstarted turns after earlier players fully finish.
+Completed shipment resources, forces, cards and counters stay intact. Advanced
+Guild priority remains guarded until Guild finishes. Current private controls,
+all four AI profiles and persisted room actions reuse the same legality check;
+the card is discarded once. Other Sapho modes and release gates remain pending.
+See [runtime scope](JUICE_OF_SAPHO_RUNTIME.md).
+
+Four new engine tests include genuine Advanced setup and owner-only rendered
+controls. One independent SQLite test exercises real completed shipment,
+restart, concurrent claims, physical custody and replay rejection. Independent
+review found no blocker. Checkpoint-wide results and the final source fingerprint
+are recorded in the commit and private report.
+
+The user reported a power outage during this work. The existing server was
+healthy, all 291 rooms were present, SQLite integrity/foreign-key checks passed,
+and all 218 rooms in the prior opening baseline matched. QA room `2EMYG4CY`
+restored its same private hand, resources and pending Storm choice after refresh.
+All 291 rooms were backed up before further work; no reset or restart occurred.
+
+The independent [Leader Skills source contract](LEADER_SKILLS_RULES.md) supplies
+the complete fourteen-card inventory and shared lifecycle for the next batch.
+It records unresolved edges and establishes no runtime prototype or mode gate.
+
 ## 13 September 2026 — Discovery location effects prototype
 
 Adds automatic unambiguous Jacurutu battle income, an owned Testing Station