Say that a file is stored where it is chosen, not on Save

Replacing a file uploads it straight away, while every other input waits
for the Save at the foot of the panel. Nothing said so, so a replacement
left the footer reading "All changes saved" with Save greyed out - which
is exactly what an edit that failed to register looks like.

The row now says it, and a test covers the path it describes: Replace
reopens the picker and the chosen file uploads on its own.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/app/shared/task-execution-inputs-panel/task-execution-inputs-panel.css

@@ -398,6 +398,13 @@
   word-break: break-all;
 }
 
+.inputs-panel-upload-note {
+  margin-top: 4px;
+  color: #94a3b8;
+  font-size: 10.5px;
+  line-height: 1.4;
+}
+
 .inputs-panel-items {
   display: flex;
   flex-direction: column;

src/app/shared/task-execution-inputs-panel/task-execution-inputs-panel.html

@@ -277,6 +277,13 @@
         {{ uploadError }}
       </span>
     </div>
+    } @else if (executionInput.provided && !isInputSaving(executionInput.key)) {
+    <!--
+      A file is stored the moment it is chosen, while every other input waits for the Save below.
+      Without saying so, replacing one left the footer reading "All changes saved" with Save greyed -
+      which is what an edit that did not register would look like.
+    -->
+    <div class="inputs-panel-upload-note">Stored as soon as it is chosen; the Save below is for the other inputs.</div>
     }
     } @else if (isMultipleInput(executionInput)) {
     @if (itemsOpen(executionInput)) {

src/app/shared/task-execution-inputs-panel/task-execution-inputs-panel.spec.ts

@@ -168,6 +168,44 @@ describe('TaskExecutionInputsPanelComponent', () => {
     expect(text).toContain('Node inputs');
   });
 
+  it('uploads again when an already-provided file is replaced', async () => {
+    const fixture = await build([makeInput({
+      key: 'global:document',
+      inputName: 'document',
+      type: 'FILE',
+      multiple: false,
+      value: '/tmp/upload-1/plan-01.pdf',
+      provided: true
+    })]);
+    // Nothing is missing, so the group starts closed: open it to reach the row.
+    fixture.componentInstance.toggleGlobals();
+    fixture.detectChanges();
+
+    // A provided file shows what it holds, with Replace rather than a picker to hunt for.
+    expect(fixture.nativeElement.textContent).toContain('plan-01.pdf');
+    const replace = fixture.nativeElement.querySelector('.inputs-panel-upload-replace') as HTMLButtonElement;
+    expect(replace).toBeTruthy();
+
+    const picker = fixture.nativeElement.querySelector('input[type="file"]') as HTMLInputElement;
+    const clicked = vi.fn();
+    picker.addEventListener('click', clicked);
+    replace.click();
+    expect(clicked).toHaveBeenCalled();
+
+    const uploads = vi.fn();
+    fixture.componentInstance.fileInputChange.subscribe(uploads);
+    const replacement = new File(['%PDF-1.7'], 'plan-02.pdf', { type: 'application/pdf' });
+    Object.defineProperty(picker, 'files', { value: [replacement], configurable: true });
+    picker.dispatchEvent(new Event('change'));
+
+    // The replacement uploads on its own: a file is stored where it is chosen, not on a later save.
+    expect(uploads).toHaveBeenCalledTimes(1);
+    expect(uploads.mock.calls[0][0].files[0].name).toBe('plan-02.pdf');
+    // And the row says so, since the footer's Save stays greyed and would otherwise read as an
+    // edit that did not register.
+    expect(fixture.nativeElement.textContent).toContain('Stored as soon as it is chosen');
+  });
+
   it('offers a single save for every pending edit', async () => {
     const fixture = await build(
       [makeInput({ key: 'g:a', inputName: 'a' }), makeInput({ key: 'g:b', inputName: 'b' })],
@@ -519,4 +557,5 @@ describe('parseJsonArrayInput', () => {
   it('converts plain numbers and booleans to text', () => {
     expect(parseJsonArrayInput('[1, true]').values).toEqual(['1', 'true']);
   });
+
 });