feat: a tick keeps looking back 30 days, so an EDITED post is reached (4386)

Operator, 2026-09-23, on a Floppystack post: "this post has been updated as
he implements hot fixes — any chance we have a way to scan for or see updated
posts so we can update ours to match and pull the new attachments and
pictures etc."

The download half already worked: extract_media reads the media list off the
LIVE feed response every walk, so a newly attached hotfix build is a ledger
key we have never seen. Only REACHING the post was missing — a tick stopped
after 20 contiguous already-have-it items, and a post edited three days after
publication sits well below twenty. Not a bug in the early-out; a count
cannot express "recent".

The early-out now needs BOTH conditions: the run of seen items AND a post
published before the horizon. Strictly a widening — window 0 is exactly the
old behaviour, and no window can make a tick stop EARLIER than it used to, so
a source paused for months still walks its whole unseen backlog. The horizon
is a floor on how far to look, never a ceiling.

Inside the window the post-record gate is bypassed too (write_post_record
revisit=True): the body is re-read from the feed response already in hand, so
a revisit costs zero requests, and a body that comes back empty writes
NOTHING rather than blanking one a detail-fetch had filled. Revisits are kept
out of the #862 body-drift canary's sample for the same reason — an empty
revisit is healthy, and counting it would walk the alarm toward firing on
good ticks.

The run summary names what changed ("3 post(s) updated (5 new file(s))") with
a line per post; the ask was to SEE updated posts, not only to end up with
their bytes.

download_revisit_days is a settings row, not a constant (rule 25) — how long
a creator keeps editing is a property of the creator. Default 30, 0 turns it
off. Migration 0108.

Also corrects two stale docstrings: both clients described post_meta as
feeding an Ingester.preview that no longer calls it. It had no consumer at
all until this change.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LVjrnpQjRgHdvq95rASoiR

frontend/src/components/subscriptions/SettingsTab.vue

@@ -153,6 +153,24 @@
             </div>
           </v-col>
         </v-row>
+        <v-row>
+          <v-col cols="12" sm="4">
+            <v-text-field
+              v-model.number="dl.download_revisit_days"
+              label="Re-check edited posts (days)"
+              type="number" :min="0" :max="365"
+              density="compact" hide-details
+              @blur="saveDownloader"
+            />
+            <div class="fc-help">
+              A routine check keeps looking back this far after it runs out of
+              new posts, so a creator who edits an older post to add a file is
+              still picked up. New attachments download; the post text is
+              re-read from the same page, costing nothing extra. 0 turns this
+              off. Default 30.
+            </div>
+          </v-col>
+        </v-row>
         <v-alert v-if="importStore.settingsError" type="error" variant="tonal" class="mt-2" closable>
           {{ importStore.settingsError }}
         </v-alert>
@@ -209,6 +227,7 @@ const dl = reactive({
   download_schedule_default_seconds: 28800,
   download_event_retention_days: 90,
   download_failure_warning_threshold: 5,
+  download_revisit_days: 30,
   extdl_mega_enabled: true,
   extdl_gdrive_enabled: true,
   extdl_mediafire_enabled: true,