refactor(web): extract allocation drag session

scripts/check-architecture-guardrails.mjs

@@ -340,6 +340,17 @@ export const rules = [
     ],
     forbidden: [],
   },
+  {
+    file: "apps/web/src/hooks/timelineAllocationDragSession.ts",
+    maxLines: 70,
+    required: [
+      {
+        pattern: /\bexport function beginAllocationDragSession\b/,
+        message: "timeline allocation drag session helpers must keep document drag lifecycle centralized",
+      },
+    ],
+    forbidden: [],
+  },
   {
     file: "apps/web/src/hooks/timelineProjectDrag.ts",
     maxLines: 80,
@@ -429,6 +440,10 @@ export const rules = [
         pattern: /from "\.\/timelineAllocationDragState\.js"/,
         message: "timeline drag must keep allocation drag bootstrap delegated to the extracted helper module",
       },
+      {
+        pattern: /from "\.\/timelineAllocationDragSession\.js"/,
+        message: "timeline drag must keep allocation drag document session wiring delegated to the extracted helper module",
+      },
       {
         pattern: /from "\.\/timelineProjectDrag\.js"/,
         message: "timeline drag must keep project drag bootstrap and mutation gating delegated to the extracted helper module",
@@ -483,6 +498,10 @@ export const rules = [
         pattern: /\bfunction createAllocationDragState\b/,
         message: "timeline drag must not re-inline extracted allocation drag bootstrap helpers",
       },
+      {
+        pattern: /\bfunction handle(?:Move|Up)\b/,
+        message: "timeline drag must not re-inline extracted allocation drag session handlers",
+      },
       {
         pattern: /\bfunction (?:createProjectDragState|buildProjectShiftMutationInput)\b/,
         message: "timeline drag must not re-inline extracted project drag helper implementations",