feat(projects): replace numeric Intern inputs with picker

src/main/resources/static/assets/app.js

@@ -37,4 +37,57 @@ document.addEventListener('DOMContentLoaded', () => {
     try { localStorage.setItem('labtimesheet-sidebar', collapsed ? 'collapsed' : 'expanded'); }
     catch (_) { /* Collapse still works for this page. */ }
   });
+
+  document.querySelectorAll('[data-intern-picker]').forEach((picker) => {
+    const open = picker.querySelector('[data-picker-open]');
+    const dialog = picker.querySelector('[data-picker-dialog]');
+    const search = picker.querySelector('[data-picker-search]');
+    const summary = picker.querySelector('[data-picker-summary]');
+    const empty = picker.querySelector('[data-picker-empty]');
+    const cancel = picker.querySelector('[data-picker-cancel]');
+    const apply = picker.querySelector('[data-picker-apply]');
+    const options = [...picker.querySelectorAll('[data-picker-option]')];
+    let initialSelection = [];
+
+    const inputs = () => options.map((option) => option.querySelector('input'));
+    const updateSummary = () => {
+      const selected = options
+        .filter((option) => option.querySelector('input').checked)
+        .map((option) => option.querySelector('[data-picker-label]').textContent.trim());
+      summary.textContent = selected.length === 0
+        ? `No Intern${inputs()[0]?.type === 'radio' ? '' : 's'} selected`
+        : `${selected.length} Intern${selected.length === 1 ? '' : 's'} selected: ${selected.join(', ')}`;
+    };
+    const filter = () => {
+      const query = search.value.trim().toLocaleLowerCase();
+      let visible = 0;
+      options.forEach((option) => {
+        option.hidden = !option.dataset.pickerSearch.toLocaleLowerCase().includes(query);
+        if (!option.hidden) visible += 1;
+      });
+      empty.hidden = visible !== 0;
+    };
+    const restore = () => {
+      inputs().forEach((input, index) => { input.checked = initialSelection[index]; });
+      updateSummary();
+    };
+
+    inputs().forEach((input) => input.addEventListener('change', updateSummary));
+    search.addEventListener('input', filter);
+    open.addEventListener('click', () => {
+      initialSelection = inputs().map((input) => input.checked);
+      search.value = '';
+      filter();
+      dialog.showModal();
+      search.focus();
+    });
+    cancel.addEventListener('click', () => {
+      restore();
+      dialog.close();
+    });
+    dialog.addEventListener('cancel', restore);
+    dialog.addEventListener('close', () => open.focus());
+    apply.addEventListener('click', () => dialog.close());
+    updateSummary();
+  });
 });