fix(tickers): let an SEC confirmation upgrade a manual delisting mark

mark_delisted returned early on any already-delisted row, so the sequence an
operator actually hits — mark EA by hand today, Form 25-NSE surfaces three days
later dated 2026-08-04 — left the estimated date and "manual" reason in place
permanently. Form 25 carries the real effective date, so it now replaces an
operator's estimate; a confirmed row is never downgraded or re-probed.

Also cover _get_ohlcv_priority_tickers, the one place active_only wraps a
compound select rather than a bare one — the unit suite reached none of it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/services/ticker_service.py

@@ -106,9 +106,11 @@ async def mark_delisted(
 ) -> bool:
     """Record that a symbol stopped trading. True if this changed anything.
 
-    Idempotent: re-marking an already-delisted symbol is a no-op, so the
-    staleness path can call it on every run without churning the row or
-    re-emitting events.
+    Idempotent, so the staleness path can call it every run without churning the
+    row: re-marking is a no-op. The one exception is an SEC confirmation landing
+    on a row an operator marked by hand — Form 25 carries the real effective
+    date, so it replaces the operator's estimate. Nothing downgrades a confirmed
+    row back to a manual one.
     """
     normalised = symbol.strip().upper()
     result = await db.execute(select(Ticker).where(Ticker.symbol == normalised))
@@ -116,7 +118,11 @@ async def mark_delisted(
     if ticker is None:
         raise NotFoundError(f"Ticker not found: {normalised}")
     if ticker.delisted_on is not None:
-        return False
+        upgrading = (
+            reason == REASON_FORM_25 and ticker.delisted_reason != REASON_FORM_25
+        )
+        if not upgrading:
+            return False
 
     await db.execute(
         update(Ticker)
@@ -158,7 +164,11 @@ async def confirm_delisting(
     normalised = symbol.strip().upper()
     result = await db.execute(select(Ticker).where(Ticker.symbol == normalised))
     ticker = result.scalar_one_or_none()
-    if ticker is None or ticker.delisted_on is not None or not ticker.cik:
+    if ticker is None or not ticker.cik:
+        return None
+    # Already confirmed by SEC — nothing left to learn. A row an operator marked
+    # by hand is still worth probing: Form 25 upgrades the estimated date.
+    if ticker.delisted_reason == REASON_FORM_25:
         return None
     # No bars at all is an ingestion problem, not evidence of a delisting.
     if last_bar is None: