refactor(web): extract preview target setup

scripts/check-architecture-guardrails.mjs

@@ -255,6 +255,25 @@ export const rules = [
     ],
     forbidden: [],
   },
+  {
+    file: "apps/web/src/hooks/timelinePreviewSession.ts",
+    maxLines: 80,
+    required: [
+      {
+        pattern: /\bexport function createProjectPreviewSession\b/,
+        message: "timeline preview session helpers must keep project preview target resolution centralized",
+      },
+      {
+        pattern: /\bexport function createAllocationPreviewSession\b/,
+        message: "timeline preview session helpers must keep allocation preview target resolution centralized",
+      },
+      {
+        pattern: /from "\.\/timelineLivePreview\.js"/,
+        message: "timeline preview session helpers must keep target capture delegated to the live preview helper module",
+      },
+    ],
+    forbidden: [],
+  },
   {
     file: "apps/web/src/hooks/timelineAllocationFinalize.ts",
     maxLines: 100,
@@ -492,6 +511,10 @@ export const rules = [
         pattern: /from "\.\/timelineOptimisticAllocations\.js"/,
         message: "timeline drag must keep optimistic allocation reconciliation delegated to the extracted helper module",
       },
+      {
+        pattern: /from "\.\/timelinePreviewSession\.js"/,
+        message: "timeline drag must keep preview target setup delegated to the extracted helper module",
+      },
       {
         pattern: /from "\.\/timelineDragCleanup\.js"/,
         message: "timeline drag must keep unmount teardown delegated to the extracted helper module",
@@ -594,6 +617,14 @@ export const rules = [
         pattern: /\bconst mutationInput = buildProjectShiftMutationInput\(finalDrag\)\b[\s\S]*applyShiftMutation\.(?:mutate|mutateAsync)\(/,
         message: "timeline drag must not re-inline extracted project drag finalize flow",
       },
+      {
+        pattern: /\bdocument\.querySelectorAll<HTMLElement>\([\s\S]*data-timeline-project-id/,
+        message: "timeline drag must not re-inline extracted project preview target lookup",
+      },
+      {
+        pattern: /\bcurrentTarget\.closest<HTMLElement>\('\[data-timeline-drag-preview~=\"allocation\"\]'\)/,
+        message: "timeline drag must not re-inline extracted allocation preview target lookup",
+      },
       {
         pattern: /\bconst selection = finalizeRangeSelection\(/,
         message: "timeline drag must not re-inline extracted range release resolution",