refactor(web): extract project drag finalize

scripts/check-architecture-guardrails.mjs

@@ -412,6 +412,25 @@ export const rules = [
     ],
     forbidden: [],
   },
+  {
+    file: "apps/web/src/hooks/timelineProjectDragFinalize.ts",
+    maxLines: 60,
+    required: [
+      {
+        pattern: /\bexport function finalizeProjectDrag\b/,
+        message: "timeline project drag finalize helpers must keep completion flow centralized",
+      },
+      {
+        pattern: /from "\.\/timelineProjectDrag\.js"/,
+        message: "timeline project drag finalize helpers must keep mutation gating delegated to the project drag helper module",
+      },
+      {
+        pattern: /from "\.\/timelineLivePreview\.js"/,
+        message: "timeline project drag finalize helpers must keep preview preservation delegated to the live preview helper module",
+      },
+    ],
+    forbidden: [],
+  },
   {
     file: "apps/web/src/hooks/timelineProjectDragSession.ts",
     maxLines: 70,
@@ -484,7 +503,11 @@ export const rules = [
       },
       {
         pattern: /from "\.\/timelineProjectDrag\.js"/,
-        message: "timeline drag must keep project drag bootstrap and mutation gating delegated to the extracted helper module",
+        message: "timeline drag must keep project drag bootstrap delegated to the extracted helper module",
+      },
+      {
+        pattern: /from "\.\/timelineProjectDragFinalize\.js"/,
+        message: "timeline drag must keep project drag completion delegated to the extracted helper module",
       },
       {
         pattern: /from "\.\/timelineProjectDragSession\.js"/,
@@ -544,6 +567,10 @@ export const rules = [
         pattern: /\bfunction (?:createProjectDragState|buildProjectShiftMutationInput)\b/,
         message: "timeline drag must not re-inline extracted project drag helper implementations",
       },
+      {
+        pattern: /\bconst mutationInput = buildProjectShiftMutationInput\(finalDrag\)\b[\s\S]*applyShiftMutation\.(?:mutate|mutateAsync)\(/,
+        message: "timeline drag must not re-inline extracted project drag finalize flow",
+      },
     ],
   },
   {