fix(projects): preserve server picker recovery

docs/tests/web/project-intern-picker.md

@@ -21,6 +21,8 @@ The combined Java RED command was `env JAVA_HOME=/opt/homebrew/opt/openjdk@25 PA
 
 After the producer API compiled, `env JAVA_HOME=/opt/homebrew/opt/openjdk@25 PATH=/opt/homebrew/opt/openjdk@25/bin:$PATH ./mvnw '-Dtest=ProjectControllerTest' test` ran 19 tests with 4 expected assertion failures for the missing eligible-option model, filtered multi-select markup, and retained selection rendering. A separate no-roster regression ran 1 test with 1 assertion failure because the disabled picker trigger had no reachable explanatory copy.
 
+Independent review added rendered regressions before the correction. The same focused controller command ran 22 tests with exactly 3 failures and no errors: both closed-dialog radio contracts detected browser `required`, and stale batch recovery lacked the count-only replacement message. The new missing-selection POST contracts already passed through server Bean Validation.
+
 ## GREEN
 
 `env JAVA_HOME=/opt/homebrew/opt/openjdk@25 PATH=/opt/homebrew/opt/openjdk@25/bin:$PATH ./mvnw '-Dtest=ProjectControllerTest' test` passed the initial rendered picker suite at 19/19. After adding the no-roster regression, the affected Project command below passed the expanded controller suite at 20/20.
@@ -29,6 +31,8 @@ After the producer API compiled, `env JAVA_HOME=/opt/homebrew/opt/openjdk@25 PAT
 
 `env PATH=/opt/homebrew/opt/node@24/bin:$PATH npm run build` succeeded with Tailwind CSS 4.3.3 and the existing local icon builder. No dependency was added.
 
+After the review correction, the focused controller command passed 22/22. Creation and leadership radios no longer use closed-dialog browser constraint validation; missing selections re-render their server field errors. A failed member batch retains submitted option 21 when refreshed eligibility contains only 21, omits all rendered value/ID markup for stale option 22, and reports one unavailable selection without exposing its identifier.
+
 ## Affected suite
 
 `env JAVA_HOME=/opt/homebrew/opt/openjdk@25 PATH=/opt/homebrew/opt/openjdk@25/bin:$PATH DOCKER_HOST=unix:///Users/sechmachine/.orbstack/run/docker.sock ./mvnw '-Dtest=ProjectControllerTest,ProjectEntityTest,ProjectPersistenceStructureTest,ProjectServiceIntegrationTest,ProjectTaskMutationContextTest,LayerStructureTest' test` passed 38/38 tests with no failures, errors, or skips.
@@ -39,4 +43,6 @@ After the producer API compiled, `env JAVA_HOME=/opt/homebrew/opt/openjdk@25 PAT
 
 No browser loop or Impeccable detector is run on this branch; the root owner performs one integrated pass. MockMvc proves rendered semantics and a dependency-free Node test executes the dialog/search/selection behavior with controlled DOM boundaries.
 
-After merging exact reviewed `main` `32c8a2d315d2175760c5d4792988cd0aa5ab6dd0`, `npm ci`, the 1/1 UI test, frontend build, compile, Project-scoped Javadoc/doclint, and diff check all succeeded. The affected Java command added the updated shared `UiContractWebTest` and passed 45/45 tests with no failures, errors, or skips.
+After merging exact reviewed `main` `32c8a2d315d2175760c5d4792988cd0aa5ab6dd0`, `npm ci`, the 1/1 UI test, frontend build, compile, Project-scoped Javadoc/doclint, and diff check all succeeded. The first affected Java command added the updated shared `UiContractWebTest` and passed 45/45 tests with no failures, errors, or skips.
+
+The bounded post-review affected command reran `ProjectControllerTest,ProjectEntityTest,ProjectPersistenceStructureTest,ProjectServiceIntegrationTest,ProjectTaskMutationContextTest,LayerStructureTest,UiContractWebTest` and passed 47/47 with no failures, errors, or skips, including 9/9 Project service tests against PostgreSQL 18.4. The UI test remained 1/1; frontend build, compile, Project-scoped Javadoc/doclint, and `git diff --check` also succeeded.

src/main/java/com/lab/labtimesheet/feature/project/controller/ProjectController.java

@@ -164,8 +164,8 @@ public class ProjectController {
     }
 
     /**
-     * Adds all selected eligible Interns atomically or re-renders membership history with the
+     * Adds all selected eligible Interns atomically or re-renders membership history with every
-     * complete retained selection and a safe validation message.
+     * still-eligible selection retained and a count of unavailable choices.
      *
      * @param principal authenticated user
      * @param projectId owning Project identifier
@@ -182,16 +182,27 @@ public class ProjectController {
             BindingResult bindingResult,
             Model model) {
         long actorId = actorId(principal);
+        boolean rejectedByService = false;
         if (!bindingResult.hasErrors()) {
             try {
                 projects.addMembers(actorId, projectId, membersForm.internUserIds());
                 return "redirect:/projects/" + projectId + "/members";
             } catch (ProjectRuleViolationException exception) {
+                rejectedByService = true;
                 bindingResult.rejectValue(
                         "internUserIds", "project.members.ineligible", exception.getMessage());
             }
         }
-        populateMembersModel(actorId, projectId, model);
+        var refreshedOptions = populateMembersModel(actorId, projectId, model);
+        if (rejectedByService) {
+            Set<Long> refreshedIds = refreshedOptions.stream()
+                    .map(EligibleInternOption::userId)
+                    .collect(Collectors.toUnmodifiableSet());
+            long unavailableSelectionCount = membersForm.internUserIds().stream()
+                    .filter(userId -> !refreshedIds.contains(userId))
+                    .count();
+            model.addAttribute("unavailableSelectionCount", unavailableSelectionCount);
+        }
         return "projects/members";
     }
 
@@ -242,7 +253,7 @@ public class ProjectController {
         return "projects/leadership";
     }
 
-    private void populateMembersModel(long actorId, long projectId, Model model) {
+    private List<EligibleInternOption> populateMembersModel(long actorId, long projectId, Model model) {
         var project = pages.detail(actorId, projectId);
         var members = pages.members(actorId, projectId);
         model.addAttribute("project", project);
@@ -252,10 +263,13 @@ public class ProjectController {
                     .filter(member -> member.leftAt() == null)
                     .map(member -> member.internUserId())
                     .collect(Collectors.toUnmodifiableSet());
-            model.addAttribute("eligibleInternOptions", eligibleInternOptions().stream()
+            var options = eligibleInternOptions().stream()
                     .filter(option -> !currentMemberIds.contains(option.userId()))
-                    .toList());
+                    .toList();
+            model.addAttribute("eligibleInternOptions", options);
+            return options;
         }
+        return List.of();
     }
 
     private void populateLeadershipModel(long actorId, long projectId, Model model) {

src/main/resources/templates/projects/form.html

@@ -41,7 +41,7 @@
                         <input class="control" id="leader-search" type="search" autocomplete="off" data-picker-search>
                         <div class="picker-options">
                             <label class="picker-option" data-picker-option th:each="option : ${eligibleInternOptions}" th:attr="data-picker-search=${option.displayName + ' ' + option.studentCode}">
-                                <input type="radio" th:field="*{initialLeaderUserId}" th:value="${option.userId}" required>
+                                <input type="radio" th:field="*{initialLeaderUserId}" th:value="${option.userId}">
                                 <span><strong data-picker-label th:text="|${option.displayName} (${option.studentCode})|">Intern (Code)</strong><small th:text="|${#temporals.format(option.internshipStart, 'dd/MM/yyyy')} – ${#temporals.format(option.internshipEnd, 'dd/MM/yyyy')}|">Dates</small></span>
                             </label>
                             <p class="picker-empty" data-picker-empty th:hidden="${!#lists.isEmpty(eligibleInternOptions)}">No matching eligible Interns.</p>

src/main/resources/templates/projects/leadership.html

@@ -36,7 +36,7 @@
                     <input class="control" id="leadership-search" type="search" autocomplete="off" data-picker-search>
                     <div class="picker-options">
                         <label class="picker-option" data-picker-option th:each="option : ${eligibleInternOptions}" th:attr="data-picker-search=${option.displayName + ' ' + option.studentCode}">
-                            <input type="radio" th:field="*{internUserId}" th:value="${option.userId}" required>
+                            <input type="radio" th:field="*{internUserId}" th:value="${option.userId}">
                             <span><strong data-picker-label th:text="|${option.displayName} (${option.studentCode})|">Intern (Code)</strong><small th:text="|${#temporals.format(option.internshipStart, 'dd/MM/yyyy')} – ${#temporals.format(option.internshipEnd, 'dd/MM/yyyy')}|">Dates</small></span>
                         </label>
                         <p class="picker-empty" data-picker-empty th:hidden="${!#lists.isEmpty(eligibleInternOptions)}">No matching eligible current members.</p>

src/main/resources/templates/projects/members.html

@@ -29,6 +29,8 @@
             <p class="picker-summary" data-picker-summary aria-live="polite">No Interns selected</p>
             <p class="field-help" th:if="${#lists.isEmpty(eligibleInternOptions)}">No eligible nonmembers are available.</p>
             <p class="field-error" id="member-intern-user-error" role="alert" th:if="${#fields.hasErrors('internUserIds')}" th:errors="*{internUserIds}"></p>
+            <p class="field-help" role="status" th:if="${unavailableSelectionCount != null and unavailableSelectionCount > 0}"
+               th:text="${unavailableSelectionCount == 1 ? '1 previously selected Intern is no longer eligible; choose a replacement.' : unavailableSelectionCount + ' previously selected Interns are no longer eligible; choose replacements.'}">Unavailable selection recovery</p>
             <dialog class="picker-drawer" data-picker-dialog aria-labelledby="member-picker-title">
                 <div class="picker-header"><div><h2 class="panel-title" id="member-picker-title">Add Project members</h2><p class="field-help">Select one or more eligible Interns who are not current members.</p></div><button class="button" type="button" data-picker-cancel>Cancel</button></div>
                 <div class="picker-body">

src/test/java/com/lab/labtimesheet/feature/project/controller/ProjectControllerTest.java

@@ -35,6 +35,7 @@ import java.time.Clock;
 import java.time.LocalDate;
 import java.time.ZoneId;
 import java.util.List;
+import java.util.regex.Pattern;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -81,7 +82,7 @@ class ProjectControllerTest {
                 option(20L, "Nguyen An", "STU-020"),
                 option(21L, "Tran Binh", "STU-021")));
 
-        mvc.perform(get("/projects/new"))
+        String html = mvc.perform(get("/projects/new"))
                 .andExpect(status().isOk())
                 .andExpect(model().attributeExists("eligibleInternOptions"))
                 .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
@@ -95,7 +96,9 @@ class ProjectControllerTest {
                 .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
                         .string(containsString("01/08/2026 – 31/12/2026")))
                 .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
-                        .string(not(containsString("Initial Leader user ID"))));
+                        .string(not(containsString("Initial Leader user ID"))))
+                .andReturn().getResponse().getContentAsString();
+        assertFalse(containsRequiredRadio(html));
     }
 
     @Test
@@ -139,17 +142,17 @@ class ProjectControllerTest {
         assertTrue(leadershipHtml.contains("Current Member"));
         assertFalse(leadershipHtml.contains("Eligible Nonmember"));
         assertFalse(leadershipHtml.contains("data-picker-label>Current Leader"));
+        assertFalse(containsRequiredRadio(leadershipHtml));
     }
 
     @Test
     @WithMockUser(username = "mentor@example.test")
-    void rejectedMemberBatchRetainsEverySelectionAndShowsRecoveryCopy() throws Exception {
+    void rejectedMemberBatchRetainsEligibleSelectionsAndExplainsUnavailableCountWithoutIds() throws Exception {
         when(pages.authenticatedUserId("mentor@example.test")).thenReturn(10L);
         when(pages.detail(10L, 30L)).thenReturn(plannedOwnerDetail());
         when(pages.members(10L, 30L)).thenReturn(List.of());
         when(accounts.eligibleInternOptions(LocalDate.of(2026, 8, 15))).thenReturn(List.of(
-                option(21L, "First Intern", "STU-021"),
+                option(21L, "First Intern", "STU-021")));
-                option(22L, "Second Intern", "STU-022")));
         doThrow(new ProjectRuleViolationException("One or more selected Interns are no longer eligible"))
                 .when(projects).addMembers(10L, 30L, List.of(21L, 22L));
 
@@ -161,10 +164,12 @@ class ProjectControllerTest {
                 .andExpect(model().attributeHasFieldErrors("projectMembersForm", "internUserIds"))
                 .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
                         .string(containsString("One or more selected Interns are no longer eligible")))
+                .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
+                        .string(containsString("1 previously selected Intern is no longer eligible; choose a replacement.")))
                 .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
                         .string(containsString("value=\"21\" id=\"internUserIds1\" name=\"internUserIds\" checked=\"checked\"")))
                 .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
-                        .string(containsString("value=\"22\" id=\"internUserIds2\" name=\"internUserIds\" checked=\"checked\"")));
+                        .string(not(containsString("value=\"22\""))));
     }
 
     @Test
@@ -281,6 +286,50 @@ class ProjectControllerTest {
                 .andExpect(redirectedUrl("/projects/30"));
     }
 
+    @Test
+    @WithMockUser(username = "mentor@example.test")
+    void missingInitialLeaderReRendersServerFieldError() throws Exception {
+        when(pages.authenticatedActor("mentor@example.test"))
+                .thenReturn(new ProjectActorView(10L, "MENTOR"));
+
+        mvc.perform(post("/projects")
+                        .with(csrf())
+                        .param("name", "Intern Portal Refresh")
+                        .param("startDate", "2026-08-15")
+                        .param("endDate", "2026-09-30"))
+                .andExpect(status().isOk())
+                .andExpect(view().name("projects/form"))
+                .andExpect(model().attributeHasFieldErrors("projectForm", "initialLeaderUserId"))
+                .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
+                        .string(containsString("id=\"initialLeaderUserId-error\"")));
+
+        verify(projects, never()).create(org.mockito.ArgumentMatchers.anyLong(), org.mockito.ArgumentMatchers.any());
+    }
+
+    @Test
+    @WithMockUser(username = "mentor@example.test")
+    void missingReplacementLeaderReRendersServerFieldError() throws Exception {
+        when(pages.authenticatedUserId("mentor@example.test")).thenReturn(10L);
+        when(pages.detail(10L, 30L)).thenReturn(plannedOwnerDetail());
+        when(pages.leadership(10L, 30L)).thenReturn(List.of());
+        when(pages.members(10L, 30L)).thenReturn(List.of(new ProjectMemberView(
+                41L, 21L, "Current Member", Instant.parse("2026-08-15T00:00:00Z"), null, false)));
+        when(accounts.eligibleInternOptions(LocalDate.of(2026, 8, 15))).thenReturn(List.of(
+                option(21L, "Current Member", "STU-021")));
+
+        mvc.perform(post("/projects/30/leadership").with(csrf()))
+                .andExpect(status().isOk())
+                .andExpect(view().name("projects/leadership"))
+                .andExpect(model().attributeHasFieldErrors("projectMemberForm", "internUserId"))
+                .andExpect(org.springframework.test.web.servlet.result.MockMvcResultMatchers.content()
+                        .string(containsString("id=\"leadership-intern-user-error\"")));
+
+        verify(projects, never()).changeLeader(
+                org.mockito.ArgumentMatchers.anyLong(),
+                org.mockito.ArgumentMatchers.anyLong(),
+                org.mockito.ArgumentMatchers.anyLong());
+    }
+
     @Test
     @WithMockUser(username = "mentor@example.test")
     void owningMentorCanActivateAPlannedProject() throws Exception {
@@ -521,4 +570,10 @@ class ProjectControllerTest {
                 LocalDate.of(2026, 8, 1),
                 LocalDate.of(2026, 12, 31));
     }
+
+    private static boolean containsRequiredRadio(String html) {
+        return Pattern.compile("<input(?=[^>]*type=\\\"radio\\\")(?=[^>]*required(?:=|\\s|>))[^>]*>")
+                .matcher(html)
+                .find();
+    }
 }