Add message links, suspect retries, and Discord preview recovery

docs/media-scraper.md

@@ -210,6 +210,25 @@ a cached still show a labeled placeholder, and playback streams only when the us
 GIF hover plays the animated GIF cached in `thumbs/` (the original is kept alongside the static
 frame and referenced by `anim_hash`), never the provider, so scrolling cannot spam anyone.
 
+## Failure policy and recovery
+
+The archive never treats a transient HTTP answer as a dead link on the first try.
+
+- A preview or download that fails with an HTTP status on Discord's CDN is retried once with a
+  **refreshed URL** from the source message (the signed link expires in about a day). Only if the
+  refreshed fetch fails is the row parked.
+- Parked rows become **suspects**: they get one delayed retry (about 50 s). The retry runs after
+  the batch, not immediately. If a batch is two-thirds suspect failures, the cooldown doubles
+  (floor 60 s) and the retries run before the next batch.
+- A suspect whose delayed retry fails again is left **unverified**: it is skipped by later passes,
+  so a finished backfill never churns over genuinely unavailable media. The Bot tab shows suspects
+  and unverified counts per member, and the progress bar fills blue for cached, gray for pending,
+  and red for failed rows.
+- **Recover Discord previews** is a one-shot task in the Bot tab: it walks every scrape's
+  Discord-CDN rows closed with HTTP errors, refreshes each URL through the message (slopbot REST or
+  the puppet, whichever the scrape used), and fetches the preview again. It starts paused; when it
+  finishes it moves to the task history. The code stays for reuse.
+
 ## Bot tab settings
 
 The Bot tab owns the tunables; they persist in `preferences.json` and apply to live jobs at once.

docs/media.md

@@ -101,6 +101,9 @@ media-scrape/db/
 - The grid never renders an embed's page URL as media. A direct video file without a preview shows
   a first-frame `<video>` only for playable containers (mp4, webm, m4v); anything else shows a
   labeled placeholder, and a failed image falls back to that placeholder.
+- Every item carries the permanent Discord message link (`messageUrl`) derived from
+  `media_sources`; the viewer shows it (with a copy button) instead of the expiring CDN URL, and
+  "View full" streams through the daemon so the source is refreshed automatically.
 - Every item records who posted it, when, and its dimensions: `author_id`, `author_name`,
   `posted_at`, `width`, `height`, and `aspect_ratio`. In `download` mode a missing resolution is
   filled in with `ffprobe` after the file lands.

docs/webui.md

@@ -166,7 +166,10 @@ box live in Chat, not Call, and the connection stats are not chips yet.
   file, then the CDN URL; videos and audio are link cards with the poster and posted time in the
   tooltip.
 - Bot shows the slopbot connection state, the backfill queue (previews), the **Titles (YouTube)**
-  catch-up lane with its own Start/Pause, and the media tunables. Backfill has
+  catch-up lane with its own Start/Pause, the one-shot **Recover Discord previews** task, the task
+  history, the failure-policy hint, and the media tunables. Media items carry their permanent
+  `messageUrl`; the viewer shows it with a **Copy link** button in the link popup and offers
+  **Open on YouTube** as a fallback for embeds that refuse to play. Backfill has
   totals and an ETA with a Bot/Puppet split, then one job card per chat with its member scrapes,
   per-kind pending, a progress bar, an ETA, and Start/Pause; the header has **Start backfill** and
   **Pause all**. A red banner reads `API timed out, increase timers` during a Discord cooldown. The
@@ -306,6 +309,9 @@ replaceable.
 | GET | `/api/media/titles` | none | Title catch-up lane: state, pending/resolved/failed, throughput, ETA, current scrape |
 | POST | `/api/media/titles/start` | none | Start the title lane |
 | POST | `/api/media/titles/pause` | none | Pause the title lane after the current batch |
+| GET | `/api/media/recover` | none | Recovery task state, remaining Discord-CDN preview failures, counts, and the task history |
+| POST | `/api/media/recover/start` | none | Start the Discord preview recovery task |
+| POST | `/api/media/recover/pause` | none | Pause the recovery task after the current row |
 | GET | `/api/media/authors` | none | Distinct posters across every scrape, with counts |
 | GET | `/api/media/stats` | same filters as `/api/media` | Counts per kind (`image`, `gif`, `video`, `audio`), each with `total`, `downloaded`, `cached`, `notDownloaded` |
 | GET | `/api/media/storage` | none | Usage against the limit, per-kind sizes, `nearLimit`; marks old scrapes when over |