fix(firms): reject impossible acquisition days in CSV parsing

Rebased onto current main with review follow-ups folded in.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

docs/CURRENT-STATE.md

@@ -1429,6 +1429,8 @@ accessible name remains "Don't show this again". Control behavior is unchanged.
 
 ## FIRMS source status
 
+The FIRMS CSV parser rejects impossible acquisition calendar dates before the proxy filters records to the trailing 24 hours, while retaining valid UTC acquisition times.
+
 The FIRMS proxy records source success after appending its rows. If aggregation
 throws, that source reports failure without a contradictory success entry.
 The existing per-record append continues to support large feeds; sequential