diff --git a/frontend/packages/dashboard/src/dashboard.css b/frontend/packages/dashboard/src/dashboard.css
index 70be4d8c..0f80eee4 100644
--- a/frontend/packages/dashboard/src/dashboard.css
+++ b/frontend/packages/dashboard/src/dashboard.css
@@ -481,6 +481,14 @@ body.dashboard-shell {
   padding: 0.4em 0.6em;
 }
 .tc-input:focus { outline: 1px solid var(--green); }
+/* themedPrompt's field is always a resizable textarea (Enter submits,
+   Shift+Enter inserts a newline) — sensible min-height, wrapped output. */
+.tc-textarea {
+  resize: vertical;
+  min-height: 4.5em;
+  line-height: 1.4;
+  white-space: pre-wrap;
+}
 
 /* themedToast — non-blocking transient notifications (errors/info/ok) */
 .tc-toasts {
diff --git a/frontend/packages/dashboard/src/modal.js b/frontend/packages/dashboard/src/modal.js
index fe3d05f4..1f9b511a 100644
--- a/frontend/packages/dashboard/src/modal.js
+++ b/frontend/packages/dashboard/src/modal.js
@@ -125,15 +125,27 @@ export function themedConfirm(opts = {}) {
 }
 
 // themedPrompt({ title, message, label, placeholder, value, confirmLabel, cancelLabel })
-//   → Promise<string | null>. Themed replacement for window.prompt(): an input
-//   dialog that resolves to the entered string on confirm, or null on cancel.
+//   → Promise<string | null>. Themed replacement for window.prompt(): a
+//   resizable <textarea> dialog that resolves to the entered string on confirm,
+//   or null on cancel. Chat-box key behaviour: **Enter submits**, **Shift+Enter
+//   inserts a newline** — so short answers are one keystroke while multi-line
+//   reasons (e.g. an approval deny note) are still possible. Escape cancels
+//   (via openDialog).
 export function themedPrompt(opts = {}) {
   const {
     title = '', message = '', label = '', placeholder = '', value = '',
     confirmLabel = 'ok', cancelLabel = 'cancel',
   } = opts;
-  const input = el('input', { type: 'text', class: 'tc-input', placeholder });
+  const input = el('textarea', { class: 'tc-input tc-textarea', rows: '3', placeholder });
   if (value) input.value = value;
+  // Enter submits (clicks the confirm button mounted by openDialog);
+  // Shift+Enter falls through to the textarea's default newline insert.
+  input.addEventListener('keydown', (e) => {
+    if (e.key === 'Enter' && !e.shiftKey) {
+      e.preventDefault();
+      input.closest('.tc-box')?.querySelector('.tc-confirm')?.click();
+    }
+  });
   const content = el('div', { class: 'tc-promptfield' },
     label ? el('label', { class: 'tc-promptlabel' }, label) : null,
     input);