feat: ClubLog Most Wanted rank in the entry band matrix

Opt-in (Settings → General). Shows a "MW #rank" pill next to the DXCC entity
name in the entry-strip band/slot matrix — ClubLog's Most Wanted ranking
(1 = most wanted), personalised to the operator's callsign and refreshed daily.

- internal/clublog/mostwanted.go: fetch mostwanted.php?api=1&callsign=<CALL>
  (rank→DXCC JSON, real User-Agent), invert to dxcc→rank, cache to
  <dataDir>/clublog_mostwanted.json; NeedsRefresh invalidates on callsign change.
- app.go: keyClublogMostWanted setting, a.clublogMW, startup refresh goroutine,
  activeCallsign() helper, and Get/Set/Download bindings mirroring the cty ones.
  WorkedBefore now carries MWRank (qso.WorkedBefore.MWRank) when enabled.
- BandSlotGrid.tsx: MW pill next to the entity name, colour-tiered by rank.
- SettingsModal General: toggle + download button + status, mirroring the
  ClubLog cty-exceptions block.

Also reorganises the changelog: the theme-persistence fix (landed after the
v0.20.11 tag) plus this feature go under a new 0.20.12 entry; 0.20.11 keeps only
what shipped in its binary.

frontend/wailsjs/go/models.ts

@@ -1949,6 +1949,26 @@ export namespace main {
 	        this.count = source["count"];
 	    }
 	}
+	export class ClublogMostWantedInfo {
+	    enabled: boolean;
+	    loaded: boolean;
+	    callsign: string;
+	    date: string;
+	    count: number;
+	
+	    static createFrom(source: any = {}) {
+	        return new ClublogMostWantedInfo(source);
+	    }
+	
+	    constructor(source: any = {}) {
+	        if ('string' === typeof source) source = JSON.parse(source);
+	        this.enabled = source["enabled"];
+	        this.loaded = source["loaded"];
+	        this.callsign = source["callsign"];
+	        this.date = source["date"];
+	        this.count = source["count"];
+	    }
+	}
 	export class ContestBandRow {
 	    band: string;
 	    count: number;
@@ -4225,6 +4245,7 @@ export namespace qso {
 	    dxcc_bands: string[];
 	    dxcc_modes: string[];
 	    dxcc_band_modes: BandMode[];
+	    mw_rank?: number;
 	    band_status: BandStatus[];
 	
 	    static createFrom(source: any = {}) {
@@ -4249,6 +4270,7 @@ export namespace qso {
 	        this.dxcc_bands = source["dxcc_bands"];
 	        this.dxcc_modes = source["dxcc_modes"];
 	        this.dxcc_band_modes = this.convertValues(source["dxcc_band_modes"], BandMode);
+	        this.mw_rank = source["mw_rank"];
 	        this.band_status = this.convertValues(source["band_status"], BandStatus);
 	    }