Find Library source fields by placeholder in full-stack journeys

The form gained visible Title and Content labels, so the placeholder is
no longer the accessible name. This was already failing on main.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Programcode

e2e/full-stack/case-generation.spec.ts

@@ -10,10 +10,10 @@ test("a signed-in user generates a case grounded in a saved Library source", asy
   await startDebate(page, motion);
   await page.goto("/app/library");
   await page.getByRole("button", { name: "Add Source" }).click();
-  await page.getByRole("textbox", { name: "Source title..." }).fill("Tallinn fare study");
+  await page.getByPlaceholder("Source title...").fill("Tallinn fare study");
   // Imported articles are often this long. Inlining that text in the request
   // exceeded the Edge Function's 200 KB body limit before sources loaded server-side.
-  await page.getByRole("textbox", { name: "Paste source content..." })
+  await page.getByPlaceholder("Paste source content...")
     .fill(`${marker} Tallinn ridership rose 14 percent after fares were removed. ${"Detailed ridership evidence. ".repeat(9_000)}`);
   await page.getByRole("button", { name: "Save to Library" }).click();
   await expect(page.getByText("Grounding Active")).toBeVisible();

e2e/full-stack/current-debate.spec.ts

@@ -18,8 +18,8 @@ async function snap(page: Page, name: string) {
 async function addSource(page: Page, title: string, content: string) {
   await page.goto("/app/library");
   await page.getByRole("button", { name: "Add Source" }).click();
-  await page.getByRole("textbox", { name: "Source title..." }).fill(title);
-  await page.getByRole("textbox", { name: "Paste source content..." }).fill(content);
+  await page.getByPlaceholder("Source title...").fill(title);
+  await page.getByPlaceholder("Paste source content...").fill(content);
   await page.getByRole("button", { name: "Save to Library" }).click();
   await expect(page.getByRole("switch", { name: `Toggle ${title}` })).toBeChecked();
 }

e2e/full-stack/debate-context.spec.ts

@@ -18,8 +18,8 @@ async function snap(page: Page, name: string) {
 async function addSource(page: Page, title: string, content: string) {
   await page.goto("/app/library");
   await page.getByRole("button", { name: "Add Source" }).click();
-  await page.getByRole("textbox", { name: "Source title..." }).fill(title);
-  await page.getByRole("textbox", { name: "Paste source content..." }).fill(content);
+  await page.getByPlaceholder("Source title...").fill(title);
+  await page.getByPlaceholder("Paste source content...").fill(content);
   await page.getByRole("button", { name: "Save to Library" }).click();
   await expect(page.getByRole("switch", { name: `Toggle ${title}` })).toBeChecked();
 }