fix: round €/m² in Telegram, drop "Bilder nachladen" admin button, fix lightbox visibility

- notifications: round sqm_price to whole € in Telegram match messages
  (was emitting raw float like "12.345614 €/m²").

- wohnungen: remove the admin-only "Bilder nachladen (N)" button. It
  flickered into view whenever a freshly-scraped flat was still in
  pending state, which was effectively random from the user's point of
  view, and the manual backfill it triggered isn't needed anymore — new
  flats are auto-enriched at scrape time. Also drops the dead helpers
  it was the sole caller of: enrichment.kick_backfill,
  enrichment._backfill_runner, db.flats_needing_enrichment,
  db.enrichment_counts.

- lightbox: the modal didn't appear because Tailwind's Play CDN injects
  its own .hidden { display: none } rule at runtime, which kept fighting
  our class toggle. Switch the show/hide to inline style.display so no
  external stylesheet can mask it. Single-class .lightbox now only owns
  the layout — the initial-hidden state is on the element via
  style="display:none".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/db.py

@@ -596,32 +596,6 @@ def set_flat_enrichment(flat_id: str, status: str,
         )
 
 
-def flats_needing_enrichment(limit: int = 100) -> list[sqlite3.Row]:
-    return list(_get_conn().execute(
-        """SELECT id, link FROM flats
-            WHERE enrichment_status IN ('pending', 'failed')
-            ORDER BY discovered_at DESC LIMIT ?""",
-        (limit,),
-    ).fetchall())
-
-
-def enrichment_counts() -> dict:
-    row = _get_conn().execute(
-        """SELECT
-            COUNT(*) AS total,
-            SUM(CASE WHEN enrichment_status = 'ok'      THEN 1 ELSE 0 END) AS ok,
-            SUM(CASE WHEN enrichment_status = 'pending' THEN 1 ELSE 0 END) AS pending,
-            SUM(CASE WHEN enrichment_status = 'failed'  THEN 1 ELSE 0 END) AS failed
-         FROM flats"""
-    ).fetchone()
-    return {
-        "total":   int(row["total"] or 0),
-        "ok":      int(row["ok"] or 0),
-        "pending": int(row["pending"] or 0),
-        "failed":  int(row["failed"] or 0),
-    }
-
-
 # ---------------------------------------------------------------------------
 # Applications
 # ---------------------------------------------------------------------------