fix(adif): CNTY must be STATE,COUNTY

ADIF defines CNTY as "STATE,COUNTY" — "GA,BARROW". OpsLog wrote the bare county
name, which a receiving logger cannot resolve: county names repeat across
states, and there is a Washington County in thirty of them. The award engine
here was never affected, since it reads the columns rather than the ADIF; the
damage was to every file we hand to someone else.

One writer covers everything — writeRecord — so this fixes file exports and the
LoTW, Club Log, HRDLog and QRZ uploads together. MY_CNTY gets the same
treatment.

The county alone is still written when no state is known: a bare name is worth
more than nothing, and inventing a prefix would be worse than either. A value
that already carries a comma passes through untouched, so re-exporting an
imported record cannot double the prefix.

Import is the mirror: "GA,BARROW" fills both columns, and a file carrying the
bare county — as OpsLog's own older exports do — still imports unchanged. The
state parsed out of CNTY only fills a blank STATE, never overrides it: STATE is
the dedicated field and the more specific statement.

internal/adif/fields.go

@@ -16,23 +16,23 @@ import "strings"
 type FieldKind string
 
 const (
-	KindText    FieldKind = "text"    // String / IntlString / MultilineString
-	KindNumber  FieldKind = "number"  // Number / PositiveInteger
-	KindDate    FieldKind = "date"    // ADIF Date (YYYYMMDD)
-	KindTime    FieldKind = "time"    // ADIF Time (HHMMSS / HHMM)
-	KindBool    FieldKind = "boolean" // Boolean (Y/N)
-	KindEnum    FieldKind = "enum"    // Enumeration
-	KindLoc     FieldKind = "location" // Location (e.g. "N048 09.000")
+	KindText   FieldKind = "text"     // String / IntlString / MultilineString
+	KindNumber FieldKind = "number"   // Number / PositiveInteger
+	KindDate   FieldKind = "date"     // ADIF Date (YYYYMMDD)
+	KindTime   FieldKind = "time"     // ADIF Time (HHMMSS / HHMM)
+	KindBool   FieldKind = "boolean"  // Boolean (Y/N)
+	KindEnum   FieldKind = "enum"     // Enumeration
+	KindLoc    FieldKind = "location" // Location (e.g. "N048 09.000")
 )
 
 // FieldDef describes one ADIF QSO field.
 type FieldDef struct {
-	Name       string    `json:"name"`        // canonical uppercase ADIF tag
-	Kind       FieldKind `json:"kind"`        // editor widget hint
-	Category   string    `json:"category"`    // grouping for the UI
-	Promoted   bool      `json:"promoted"`    // has a dedicated QSO column
-	Deprecated bool      `json:"deprecated"`  // import-only per the spec
-	Intl       bool      `json:"intl"`        // *_INTL UTF-8 variant
+	Name       string    `json:"name"`       // canonical uppercase ADIF tag
+	Kind       FieldKind `json:"kind"`       // editor widget hint
+	Category   string    `json:"category"`   // grouping for the UI
+	Promoted   bool      `json:"promoted"`   // has a dedicated QSO column
+	Deprecated bool      `json:"deprecated"` // import-only per the spec
+	Intl       bool      `json:"intl"`       // *_INTL UTF-8 variant
 }
 
 // adifVersion is the ADIF spec version OpsLog targets for import/export.