feat(clients): require Mother + Father/Caretaker as family members before activation

- Add hasMother/hasFather/hasCaretaker/familyRelationshipRulesMet to
  ClientFamilyMembersStepComponent, matched against the RELATIONSHIP code value label.
- Show two independent inline error banners (never merged into one message) when Mother, or
  both Father and Caretaker, are missing.
- Gate "Save & Next" and final Submit on this rule in both the create and edit client flows —
  the edit flow previously treated the Family tab as unconditionally optional.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/clients/edit-client/edit-client.component.ts

@@ -287,14 +287,20 @@ export class EditClientComponent {
     if (this.legalFormType === 2) {
       if (idx === 2) return true; // Scheme & Sector — opt-in
       if (idx === 3) return this.isAddressStepValid();
-      if (idx === 4) return true; // Family — optional
+      if (idx === 4) return true; // Family — not applicable to non-individual entities
     } else {
       if (idx === 2) return this.isAddressStepValid();
-      if (idx === 3) return true; // Family — optional
+      if (idx === 3) return this.isFamilyStepValid(); // Mother required, plus Father or a Caretaker
     }
     return true;
   }
 
+  /** Mother is required, and either Father or a Caretaker, for individual clients. */
+  private isFamilyStepValid(): boolean {
+    const step = this.clientFamilyMembersStep;
+    return !step || step.familyRelationshipRulesMet;
+  }
+
   private isAddressStepValid(): boolean {
     const step = this.clientIndiaAddressStep;
     if (!step) return true;
@@ -318,6 +324,12 @@ export class EditClientComponent {
         return `Please fill/correct: ${labels.join(', ')}.`;
       }
     }
+    const familyTabIndex = this.legalFormType === 2 ? 4 : 3;
+    if (this.selectedTabIndex === familyTabIndex && this.legalFormType !== 2 && this.clientFamilyMembersStep) {
+      const step = this.clientFamilyMembersStep;
+      if (!step.hasMother) return 'Mother is required as a family member.';
+      if (!step.hasFather && !step.hasCaretaker) return 'Either Father or a Caretaker is required as a family member.';
+    }
     return 'Please fill all mandatory fields on this tab to continue.';
   }