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

backend/app/tasks/download.py

@@ -177,6 +177,10 @@ def download_source(self, source_id: int, _serialize_waits: int = 0) -> int:
                 settings = ImportSettings.load_sync(sync_session)
                 rate_limit = settings.download_rate_limit_seconds
                 validate_files = settings.download_validate_files
+                # How far back a tick keeps looking for EDITED posts. Read here
+                # with the other downloader knobs, off the row this block is
+                # already holding open.
+                revisit_days = settings.download_revisit_days
 
             gdl = GalleryDLService(
                 images_root=IMAGES_ROOT,
@@ -207,6 +211,7 @@ def download_source(self, source_id: int, _serialize_waits: int = 0) -> int:
                         # the walk). Same factory the importer's sync session
                         # comes from — a different DB connection per checkout.
                         sync_session_factory=SyncFactory,
+                        revisit_days=revisit_days,
                     )
                     return await svc.download_source(source_id)
         finally: