Calcule date de fin en fonction du temps estimé

src/app/issues/issue-detail/issue-detail.html

@@ -162,7 +162,7 @@
               [class.is-invalid]="!!dateValidationError"
               type="date"
               [(ngModel)]="issue.startDate"
-              (blur)="saveIssue()"
+              (blur)="onStartDateBlur()"
             />
           </div>
           <div class="col-6">
@@ -170,10 +170,9 @@
             <input
               aria-label="Date de fin"
               class="form-control form-control-sm"
-              [class.is-invalid]="!!dateValidationError"
               type="date"
-              [(ngModel)]="issue.endDate"
-              (blur)="saveIssue()"
+              [ngModel]="issue.endDate"
+              readonly
             />
           </div>
           @if (dateValidationError) {

src/app/issues/issue-detail/issue-detail.spec.ts

@@ -299,6 +299,64 @@ describe('IssueDetail — existing issue', () => {
     });
   });
 
+  describe('recalculateEndDate (via estimatedTimeValue setter)', () => {
+    it('sets endDate to startDate when estimatedTime is 8h or less', () => {
+      (component as any).issue.startDate = '2026-06-01';
+      (component as any).estimatedTimeValue = 8;
+      expect((component as any).issue.endDate).toBe('2026-06-01');
+    });
+
+    it('adds one day for estimatedTime between 9h and 16h', () => {
+      (component as any).issue.startDate = '2026-06-01';
+      (component as any).estimatedTimeValue = 16;
+      expect((component as any).issue.endDate).toBe('2026-06-02');
+    });
+
+    it('adds two days for estimatedTime between 17h and 24h', () => {
+      (component as any).issue.startDate = '2026-06-01';
+      (component as any).estimatedTimeValue = 24;
+      expect((component as any).issue.endDate).toBe('2026-06-03');
+    });
+
+    it('clears endDate when startDate is empty', () => {
+      (component as any).issue.startDate = '';
+      (component as any).issue.endDate = '2026-06-05';
+      (component as any).estimatedTimeValue = 8;
+      expect((component as any).issue.endDate).toBe('');
+    });
+
+    it('clears endDate when estimatedTime is null', () => {
+      (component as any).issue.startDate = '2026-06-01';
+      (component as any).issue.endDate = '2026-06-05';
+      (component as any).estimatedTimeValue = null;
+      expect((component as any).issue.endDate).toBe('');
+    });
+
+    it('clears endDate when estimatedTime is 0', () => {
+      (component as any).issue.startDate = '2026-06-01';
+      (component as any).issue.endDate = '2026-06-05';
+      (component as any).estimatedTimeValue = 0;
+      expect((component as any).issue.endDate).toBe('');
+    });
+  });
+
+  describe('onStartDateBlur', () => {
+    it('recalculates endDate when startDate changes', () => {
+      (component as any).issue.estimatedTime = 16;
+      (component as any).issue.startDate = '2026-06-10';
+      (component as any).onStartDateBlur();
+      expect((component as any).issue.endDate).toBe('2026-06-11');
+    });
+
+    it('clears endDate when startDate is cleared', () => {
+      (component as any).issue.estimatedTime = 16;
+      (component as any).issue.endDate = '2026-06-11';
+      (component as any).issue.startDate = '';
+      (component as any).onStartDateBlur();
+      expect((component as any).issue.endDate).toBe('');
+    });
+  });
+
   describe('deleteIssue', () => {
     it('removes the issue and navigates to /issues', async () => {
       const spy = vi.spyOn(router, 'navigate').mockResolvedValue(true);

src/app/issues/issue-detail/issue-detail.ts

@@ -122,6 +122,24 @@ export class IssueDetail {
 
   protected set estimatedTimeValue(value: number | null) {
     this.issue.estimatedTime = value === null || value === undefined ? null : Number(value);
+    this.recalculateEndDate();
+  }
+
+  private recalculateEndDate(): void {
+    const { startDate, estimatedTime } = this.issue;
+    if (!startDate || estimatedTime === null || estimatedTime <= 0) {
+      this.issue.endDate = '';
+      return;
+    }
+    const start = new Date(startDate);
+    const extraDays = Math.max(0, Math.ceil(estimatedTime / 8) - 1);
+    start.setDate(start.getDate() + extraDays);
+    this.issue.endDate = start.toISOString().split('T')[0];
+  }
+
+  protected onStartDateBlur(): void {
+    this.recalculateEndDate();
+    this.saveIssue();
   }
 
   protected get issueTypeValue(): IssueEntity['type'] {