refactor: remove threads layer, use sessions directly for ACP (#9078)

Co-authored-by: Douwe Osinga <douwe@squareup.com>

ui/goose2/tests/e2e/drafts.spec.ts

@@ -8,11 +8,16 @@ async function clickNewChatInProject(
     name: projectName,
     exact: true,
   });
-  await projectButton.hover();
-  await projectButton
-    .locator("xpath=..")
-    .getByTitle("New chat in project")
-    .click();
+  // The "New chat" button uses group-hover:visible and is invisible by default.
+  // Headless Playwright on Linux doesn't reliably trigger CSS :hover,
+  // so we force the button visible via JS before clicking.
+  const row = projectButton.locator("xpath=..");
+  const newChatBtn = row.getByTitle("New chat in project");
+  await newChatBtn.evaluate((el) => {
+    el.style.visibility = "visible";
+    el.style.opacity = "1";
+  });
+  await newChatBtn.click();
 }
 
 test.describe("Draft persistence", () => {

ui/goose2/tests/e2e/fixtures/tauri-mock.ts

@@ -124,6 +124,27 @@ export function buildInitScript(options?: {
         supportingFiles: [],
       });
 
+      const projectToSourceEntry = (p) => ({
+        type: "project",
+        name: p.id ?? p.name?.toLowerCase(),
+        description: p.description ?? "",
+        content: p.prompt ?? "",
+        path: "/mock/.agents/projects/" + (p.id ?? p.name?.toLowerCase()),
+        global: true,
+        supportingFiles: [],
+        properties: {
+          title: p.name,
+          icon: p.icon ?? "",
+          color: p.color ?? "",
+          preferredProvider: p.preferredProvider ?? null,
+          preferredModel: p.preferredModel ?? null,
+          workingDirs: p.workingDirs ?? [],
+          useWorktrees: p.useWorktrees ?? false,
+          order: p.order ?? 0,
+          archivedAt: null,
+        },
+      });
+
       function nowIso() {
         return new Date().toISOString();
       }
@@ -240,8 +261,13 @@ export function buildInitScript(options?: {
           case "_goose/working_dir/update":
           case "goose/working_dir/update":
             return jsonRpcResult(message.id, {});
-          case "_goose/sources/list":
+          case "_goose/sources/list": {
+            const sourceType = message.params?.type;
+            if (sourceType === "project") {
+              return jsonRpcResult(message.id, { sources: PROJECTS.map(projectToSourceEntry) });
+            }
             return jsonRpcResult(message.id, { sources: SKILLS.map(skillToSourceEntry) });
+          }
           case "_goose/sources/create":
             return jsonRpcResult(message.id, {
               source: {

ui/goose2/tests/e2e/skills.spec.ts

@@ -52,8 +52,12 @@ test.describe("Skills view", () => {
 
     await page.getByPlaceholder("Search skills").fill("review");
 
-    await expect(page.getByText("code-review")).toBeVisible();
-    await expect(page.getByText("test-writer")).not.toBeVisible();
+    await expect(
+      page.getByRole("button", { name: "Open code-review details" }),
+    ).toBeVisible();
+    await expect(
+      page.getByRole("button", { name: "Open test-writer details" }),
+    ).not.toBeVisible();
   });
 
   test("project filtering isolates project skills", async ({