fix: a hand-assigned award reference no longer loses to the matcher

Reported on the DARC DOK award, with DL2FDM: a German address matches two or
three DOKs, the operator deletes the wrong ones and assigns the right one, and
the next recompute puts the wrong ones straight back.

The manual reference was APPENDED to what the matcher found. Storage already
kept exactly one manual entry per award — setOverrideRef drops the previous one
— so it was an override everywhere except at the one place it mattered. The
operator was arguing with the matcher and could not win.

It now replaces. The trace records what was superseded, so a corrected QSO can
still be explained rather than being merely different. A QSO with no correction
keeps every automatic reference, which the test also pins: an override must not
quietly disable matching for everyone else.

This does not address the over-matching itself — an address containing "Berlin
Mitte, 10115 Berlin" genuinely matches two DOK descriptions. That is the next
question, and a separate one.

changelog.json

@@ -4,11 +4,13 @@
     "date": "",
     "en": [
       "Serial CAT no longer keys the radio just by connecting: DTR and RTS are dropped on Xiegu, Yaesu and Kenwood as they already were on Icom — a Xiegu G90 behind a DE-19 went straight into transmit and stayed there.",
-      "Xiegu: choose how the rig is keyed — CI-V command, RTS or DTR. A G90 does not transmit on the CI-V command, so this is also what lets WSJT-X transmit through the shared CAT link."
+      "Xiegu: choose how the rig is keyed — CI-V command, RTS or DTR. A G90 does not transmit on the CI-V command, so this is also what lets WSJT-X transmit through the shared CAT link.",
+      "A reference you assign by hand now replaces what the matcher found instead of being added to it, so a correction survives the next recompute."
     ],
     "fr": [
       "Le CAT série ne met plus la radio en émission par le seul fait de se connecter : DTR et RTS sont abaissés sur Xiegu, Yaesu et Kenwood comme ils l'étaient déjà sur Icom — un Xiegu G90 derrière un DE-19 partait en émission et y restait.",
-      "Xiegu : choix du passage en émission — commande CI-V, RTS ou DTR. Un G90 n'émet pas sur la commande CI-V, c'est donc aussi ce qui permet à WSJT-X d'émettre via le partage CAT."
+      "Xiegu : choix du passage en émission — commande CI-V, RTS ou DTR. Un G90 n'émet pas sur la commande CI-V, c'est donc aussi ce qui permet à WSJT-X d'émettre via le partage CAT.",
+      "Une référence que vous affectez à la main remplace désormais ce que la détection avait trouvé au lieu de s'y ajouter : une correction survit au recalcul suivant."
     ]
   },
   {