fix(ui): add project and task error summaries

docs/tests/web/project-task-shell-integration.md

@@ -4,11 +4,12 @@
 - **Requirement IDs:** `UI-003`, `UI-004`, `UI-007`, `UI-009`, `UI-013`, `I1-UI-04`
 - **Scenario IDs:** `AC-UI-002`, `AC-UI-003`, `AC-UI-005`
 - **Test class/method:** `com.lab.labtimesheet.feature.reporting.controller.ProjectTaskShellContractTest#projectAndTaskPageUsesSharedDesktopShell`, `com.lab.labtimesheet.feature.project.controller.ProjectControllerTest`, `com.lab.labtimesheet.feature.task.controller.TaskControllerTest`
-- **Implementation commit:** `pending`
+- **Implementation and final-Project integration commits:** `401f676`, `4849e0b`
 
 ## Protected behavior
 
 Every Iteration 1 Project and Task page uses the same authenticated desktop shell, local assets, role-aware Project navigation, table containment, form controls, empty states, status badges, and `dd/MM/yyyy` date presentation. Existing capability-gated actions, server routes, validation, authentication, and CSRF contracts remain unchanged.
+Project and Task forms provide both an error summary and inline field errors for failed server validation.
 
 ## Test method
 
@@ -70,7 +71,36 @@ BUILD SUCCESS
 Total time: 4.020 s
 ```
 
-The first affected attempt additionally caught Thymeleaf trying to resolve a `null` action fragment on five pages. Replacing `null` with Thymeleaf's empty fragment token made the identical 25-test command green.
+The first affected attempt additionally caught Thymeleaf trying to resolve a `null` action fragment on five pages. Replacing `null` with Thymeleaf's empty fragment token made the identical 25-test command green. After merging the final Project activation pin, the one overlapping detail template retained both the shell and the capability-gated activation form; the focused Project/shell set passed 25 tests.
+
+Final-review form-summary regression:
+
+```text
+./mvnw -Dtest=ProjectTaskShellContractTest test
+RED: Tests run: 10, Failures: 2, Errors: 0, Skipped: 0
+Both forms were missing #fields.hasAnyErrors() and #fields.allErrors().
+
+./mvnw -Dtest=ProjectTaskShellContractTest,ProjectControllerTest,TaskControllerTest test
+GREEN: Tests run: 29, Failures: 0, Errors: 0, Skipped: 0
+BUILD SUCCESS
+Total time: 4.214 s
+```
+
+## Final delivery gate
+
+```text
+npm ci
+added 34 packages; audited 35 packages; 0 vulnerabilities
+
+npm run build
+Tailwind CSS v4.3.3: Done in 68ms
+
+./mvnw test
+PostgreSQL 18.4 via Testcontainers
+Tests run: 152, Failures: 0, Errors: 0, Skipped: 0
+36 Surefire reports
+BUILD SUCCESS
+```
 
 ## External-test boundaries