feat(review): flag handles in the review player (metadata only)

Renders run 8 frames past the cut at each end. Directors were flagging
glitches in unfixed handles as shot problems, so the player now marks
them — without trimming or burning anything into the EXRs/MOV/MP4.

- Version.handleHead/handleTail/pictureStartFrame, Export.handleHead/
  handleTail; migration backfills pipeline exports and their preview
  versions from the manifest's handleFrames (else 8)
- AE panel: "Includes handles [8] frames each end" -> manifest.review;
  older manifests fall back to source.handleFrames
- finalize copies handles onto the Version; worker 1.6.4 reports the
  head slate length (pictureStartSeconds), else the player infers it
  as MP4 frames - EXR frameCount
- Player: hatched HANDLE / SLATE regions and cut marks on the timeline,
  "HEAD/TAIL HANDLE · NOT IN EDIT" overlay on handle frames, HANDLE badge
  on notes, "Edit range only" toggle (default on in the client portal)
- Staff Handles editor on the review page for manual uploads/corrections

Also fixes two player bugs found while testing: timeToFrame floored
float error (every seek landed a frame early), and J/reverse never ran
(the keyboard effect's cleanup stopped it on the next render).

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/client/[token]/review/[versionId]/page.tsx

@@ -38,6 +38,7 @@ import {
 } from "lucide-react";
 import { useReviewStore } from "@/hooks/use-review-player";
 import { ReviewPasswordGate } from "@/components/clients/ReviewPasswordGate";
+import { HandleBadge } from "@/components/player/HandleBadge";
 
 interface Comment {
   id: string;
@@ -58,6 +59,10 @@ interface Version {
   fileUrl: string;
   fps: number;
   duration: number | null;
+  frameCount?: number | null;
+  handleHead?: number | null;
+  handleTail?: number | null;
+  pictureStartFrame?: number | null;
   approvalStatus: string;
   notes: string | null;
   // Top-level high-res flags (normalised from either shot or task.shot)
@@ -513,6 +518,10 @@ export default function ClientReviewPage({
             comments={comments as any}
             versionId={version.id}
             onAddComment={handlePlayerAddComment}
+            handles={version}
+            // The director watches the cut as cut; handles are still one
+            // toggle away, and flagged whenever the playhead is in one.
+            defaultEditRangeOnly
             saveAnnotationFn={async (data) => {
               const res = await fetch(`/api/client/${token}/annotation`, {
                 method: "POST",
@@ -644,6 +653,7 @@ export default function ClientReviewPage({
                         <span className="ml-auto font-mono text-xs text-amber-400/80">
                           {frameToTimecode(comment.frameNumber, version.fps)}
                         </span>
+                        <HandleBadge frame={comment.frameNumber} />
                       </div>
                       <p className="text-sm text-zinc-200 leading-relaxed">{comment.text}</p>
                       {comment.canEdit && (
@@ -692,8 +702,9 @@ export default function ClientReviewPage({
 
           {commentsOpen && commentFrame !== null ? (
             <div className="border-t border-zinc-800 p-3 space-y-2">
-              <p className="text-xs text-zinc-500 font-mono">
+              <p className="flex items-center gap-2 text-xs text-zinc-500 font-mono">
                 Frame {commentFrame} · {frameToTimecode(commentFrame, version.fps)}
+                <HandleBadge frame={commentFrame} />
               </p>
               <Textarea
                 placeholder="Add your note..."