feat(intake): structured per-service intake questions

Services declare up to 8 intake fields (text/yesno, required) stored
as JSONB; shared/intake.go is the single normalization point — slug
keys, label/dup/unknown-key rules, yes/no canonicalization. Booking
create validates answers against the service declaration (missing
required -> 400), unknown keys are dropped before persist.

Answers surface on UpcomingBooking and CustomerBookingView; the
services page gains a compact editor and the public form renders
declared questions under contact details. Verified live end-to-end.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/internal/shared/intake_test.go

@@ -0,0 +1,83 @@
+package shared
+
+import (
+	"strings"
+	"testing"
+
+	"bookra/apps/backend/internal/domain"
+)
+
+func TestNormalizeIntakeFields(t *testing.T) {
+	raw, err := NormalizeIntakeFields([]domain.IntakeField{
+		{Label: "First visit?", Type: "yesno", Required: true},
+		{Key: "injuries", Label: "Injuries or health notes", Type: "text"},
+	})
+	if err != nil {
+		t.Fatalf("normalize: %v", err)
+	}
+	fields := ParseIntakeFields(raw)
+	if len(fields) != 2 {
+		t.Fatalf("expected 2 fields, got %d", len(fields))
+	}
+	if fields[0].Key != "first_visit" || !fields[0].Required {
+		t.Fatalf("unexpected field normalization: %+v", fields[0])
+	}
+
+	if _, err := NormalizeIntakeFields([]domain.IntakeField{
+		{Label: "A", Type: "yesno"}, {Label: "A", Type: "text"},
+	}); err == nil {
+		t.Fatal("expected duplicate key error")
+	}
+	if _, err := NormalizeIntakeFields([]domain.IntakeField{
+		{Label: "A", Type: "radio"},
+	}); err == nil {
+		t.Fatal("expected bad type error")
+	}
+	nine := make([]domain.IntakeField, 9)
+	for i := range nine {
+		nine[i] = domain.IntakeField{Key: strings.Repeat("k", i+1), Label: "L", Type: "text"}
+	}
+	if _, err := NormalizeIntakeFields(nine); err == nil {
+		t.Fatal("expected max-8 error")
+	}
+}
+
+func TestNormalizeIntakeAnswers(t *testing.T) {
+	fields := []domain.IntakeField{
+		{Key: "first_visit", Label: "First visit?", Type: "yesno", Required: true},
+		{Key: "injuries", Label: "Injuries?", Type: "text"},
+	}
+
+	raw, err := NormalizeIntakeAnswers(fields, map[string]string{
+		"first_visit": "yes",
+		"injuries":    "  sore knee  ",
+		"undeclared":  "dropped",
+	})
+	if err != nil {
+		t.Fatalf("normalize answers: %v", err)
+	}
+	answers := ParseIntakeAnswers(raw)
+	if answers["first_visit"] != "yes" || answers["injuries"] != "sore knee" {
+		t.Fatalf("unexpected answers: %+v", answers)
+	}
+	if _, ok := answers["undeclared"]; ok {
+		t.Fatal("undeclared key should be dropped")
+	}
+
+	if _, err := NormalizeIntakeAnswers(fields, map[string]string{}); err == nil {
+		t.Fatal("expected required-field error")
+	}
+	if _, err := NormalizeIntakeAnswers(fields, map[string]string{"first_visit": "maybe"}); err == nil {
+		t.Fatal("expected yesno coercion error")
+	}
+	if _, err := NormalizeIntakeAnswers(fields, map[string]string{
+		"first_visit": "no", "injuries": strings.Repeat("x", 501),
+	}); err == nil {
+		t.Fatal("expected text cap error")
+	}
+
+	raw, err = NormalizeIntakeAnswers(nil, map[string]string{"anything": "ignored"})
+	if err != nil || raw != "{}" {
+		t.Fatalf("expected {} for no declared fields, got %q err=%v", raw, err)
+	}
+}