fix: review round 2 — Clear watch progress clears only the resume point, big view focus by the way it arrived, dialog name, reason tooltip, backfill locks

frontend/src/lib/api/feed.ts

@@ -29,10 +29,10 @@ export interface Video {
   watch_url: string;
 }
 
-/** Whether a video has anything its reset would clear: pristine = never opened, the default status
- *  and no resume position. The card's reset button and the card menu's reset both ask this. */
-export function isResettable(v: Pick<Video, "status" | "position_seconds">): boolean {
-  return v.status !== "new" || v.position_seconds > 0;
+/** Whether a video has a resume point, the one thing "Clear watch progress" clears. Its status is no
+ *  part of it: a hidden video stays hidden, a watched one watched. */
+export function hasResumePoint(v: Pick<Video, "position_seconds">): boolean {
+  return v.position_seconds > 0;
 }
 
 /** A video's related videos, in the locale YouTube fills the list in: on the video's topic, or with
@@ -290,8 +290,8 @@ export const feedApi = {
       { method: "POST", body: JSON.stringify({ status }) },
       { idempotent: true },
     ),
-  clearState: (id: string) =>
-    req(`/api/videos/${id}/state`, { method: "DELETE" }, { idempotent: true }),
+  clearProgress: (id: string) =>
+    req(`/api/videos/${id}/progress`, { method: "DELETE" }, { idempotent: true }),
   // Returns the position the server actually STORED — which is not always what we sent: a
   // trivially-early or near-finished checkpoint is cleared to 0 (see set_video_progress). Callers
   // that mirror the position into a cache must write this answer, never their own reading, so the