fix(notifications): show thumbnail image in overlay mined-card notificat

- Share generated notification icon between overlay and system notification paths
- Add `image` field to OverlayNotificationPayload; render as IMG with has-image layout
- Widen overlay stack to 420px; enlarge card padding and min-height for image variant
- Show OSD message after successful anilist retry when attempt key already handled

docs-site/anki-integration.md

@@ -223,6 +223,8 @@ Animated AVIF requires an AV1 encoder (`libaom-av1`, `libsvtav1`, or `librav1e`)
 
 `both` now means overlay + system notification. `osd` and `osd-system` are legacy config-file-only values; set `notificationType` to `"osd-system"` in `config.jsonc` if you previously used `both` and want to keep mpv OSD + system notifications. The Settings window shows `osd` or `osd-system` when already configured, but only offers `overlay`, `system`, `both`, and `none` as normal choices.
 
+When media is available, mined-card overlay and system notifications include the same current-frame thumbnail.
+
 `overwriteAudio` applies to automatic card updates and duplicate-card enrichment. Manual clipboard subtitle updates (`Ctrl/Cmd+C`, then `Ctrl/Cmd+V`) always replace generated sentence audio, while leaving the word audio field unchanged.
 
 ## AI Translation