fix(awards): add a Prefix field to the primary QSOFIELDS search

Only OrRule had a Prefix ("prepended to each found reference", e.g. postal 74 →
D74); the primary search passed "" for prefix, so an award whose references are
D01/D02… couldn't prepend the D on its main rule — only on OR fallbacks. Add
Def.Prefix, pass it into the primary run(), and expose a Prefix input next to the
primary Leading/Trailing fields in the award editor.

frontend/src/components/AwardEditor.tsx

@@ -34,7 +34,7 @@ export type AwardDef = {
   url?: string; download_url?: string; ref_url?: string; valid_from?: string; valid_to?: string; alias?: string;
   ref_display?: string; // grid column shows: ref | name | both
   type?: string; field: string; match_by?: string; exact_match?: boolean; one_ref_per_qso?: boolean; pattern: string;
-  leading_str?: string; trailing_str?: string; dynamic?: boolean;
+  leading_str?: string; trailing_str?: string; prefix?: string; dynamic?: boolean;
   or_rules?: AwardOrRule[];
   dxcc_filter: number[] | null; valid_bands?: string[]; valid_modes?: string[]; emission?: string[];
   confirm: string[] | null; validate?: string[] | null; grant_codes?: string; export_credit_granted?: boolean;
@@ -556,9 +556,10 @@ export function AwardEditor({ open, onClose, onSaved }: Props) {
                       <label className="flex items-center gap-2 text-xs cursor-pointer pl-[128px]"><Checkbox checked={!!cur.exact_match} onCheckedChange={(c) => patch({ exact_match: !!c })} /> {t('awed.exactMatch')}</label>
                       <label className="flex items-center gap-2 text-xs cursor-pointer pl-[128px]" title={t('awed.oneRefHint')}><Checkbox checked={!!cur.one_ref_per_qso} onCheckedChange={(c) => patch({ one_ref_per_qso: !!c })} /> {t('awed.oneRef')}</label>
                       <Field2 label={t('awed.patternRegex')}><Input className="h-8 font-mono text-xs" value={cur.pattern} onChange={(e) => patch({ pattern: e.target.value })} placeholder={t('awed.patternPlaceholder')} /></Field2>
-                      <div className="grid grid-cols-2 gap-3">
+                      <div className="grid grid-cols-3 gap-3">
                         <Field2 label={t('awed.leadingString')}><Input className="h-8 font-mono text-xs" value={cur.leading_str ?? ''} onChange={(e) => patch({ leading_str: e.target.value })} /></Field2>
                         <Field2 label={t('awed.trailingString')}><Input className="h-8 font-mono text-xs" value={cur.trailing_str ?? ''} onChange={(e) => patch({ trailing_str: e.target.value })} /></Field2>
+                        <Field2 label={t('awed.prefix')}><Input className="h-8 font-mono text-xs" value={cur.prefix ?? ''} onChange={(e) => patch({ prefix: e.target.value })} placeholder={t('awed.prefixPlaceholder')} title={t('awed.prefixTitle')} /></Field2>
                       </div>
 
                       {/* Fallback searches: tried in order, only while nothing