Open native advisor preparation before the first shipment

Allow Advanced BG preparation in phases2–5 at quiet boundaries, preserving
original phase/auction/readiness and native eligibility. Close a current-turn
receipt only on committed shipments, including marker and Sneak Attack entry.
Retain the legacy phase5 queue and qualify the per-territory prevention policy.
Connect persistent controls, minimal bot support and focused native evidence.
Complete modes and browser/deployed acceptance remain open.

game/karama-context.ts

@@ -179,7 +179,9 @@ const cancellationSources = {
     checks: g.battle?.powerChecks,
   }),
   advisorFlip: (g, response) =>
-    response.advisorResume === 'ambassador'
+    response.advisorPreparationSource
+      ? { preparation: response.advisorPreparationSource, window: g.advisorPreparation ?? null }
+      : response.advisorResume === 'ambassador'
       ? {
           entry: g.pendingAmbassador ?? null,
           ambassadors: g.ecazAmbassadors ?? null,