feat(uploads): choose the language of a recording; record it, show it, carry it to the engines (#61)

Form field (Swedish preselected, Other = auto) read before the file part and refused
before anything is spooled if outside the closed set; stored on the row (migration 021,
CHECK constraint, default sv for history); carried on the Job and the worker's context;
shown on the status page. Feature scenarios and the coverage map are updated, and
ADR-033/034 amended.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/uploads/intake_defaults_test.go

@@ -12,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"git.d-ma.be/mathias/tapir/internal/domain"
 	"git.d-ma.be/mathias/tapir/internal/uploads"
 )
 
@@ -21,11 +22,11 @@ func TestNewIntake_DefaultsAllowTwoReceivesPerUserAndFourOverall(t *testing.T) {
 	startSlowReceive(t, r, in, "a", 1)
 	startSlowReceive(t, r, in, "a", 2)
 
-	_, err := in.Accept(context.Background(), "a", "t", strings.NewReader("x"))
+	_, err := in.Accept(context.Background(), "a", "t", domain.LangSwedish, strings.NewReader("x"))
 	requireBusy(t, err) // a third body from one user
 
 	startSlowReceive(t, r, in, "b", 3)
 	startSlowReceive(t, r, in, "b", 4)
-	_, err = in.Accept(context.Background(), "c", "t", strings.NewReader("x"))
+	_, err = in.Accept(context.Background(), "c", "t", domain.LangSwedish, strings.NewReader("x"))
 	requireBusy(t, err) // a fifth body overall
 }