GitHub workflows (#428)

Fixes #348 
Fixes #274 
Fixes #149 

- Connect to existing repos
- Push to other branches on GitHub besides main
- Allows force push (with confirmation) dialog

---------

Co-authored-by: graphite-app[bot] <96075541+graphite-app[bot]@users.noreply.github.com>

e2e-tests/github.spec.ts

@@ -0,0 +1,145 @@
+import { expect } from "@playwright/test";
+import { test } from "./helpers/test_helper";
+
+test("should connect to GitHub using device flow", async ({ po }) => {
+  await po.setUp();
+  await po.sendPrompt("tc=basic");
+
+  await po.getTitleBarAppNameButton().click();
+  await po.githubConnector.connect();
+
+  // Wait for device flow to start and show the code
+  await expect(po.page.locator("text=FAKE-CODE")).toBeVisible();
+
+  // Verify the verification URI is displayed
+  await expect(
+    po.page.locator("text=https://github.com/login/device"),
+  ).toBeVisible();
+
+  // Verify the "Set up your GitHub repo" section appears
+  await expect(po.githubConnector.getSetupYourGitHubRepoButton()).toBeVisible();
+});
+
+test("create and sync to new repo", async ({ po }) => {
+  await po.setUp();
+  await po.sendPrompt("tc=basic");
+
+  await po.getTitleBarAppNameButton().click();
+  await po.githubConnector.connect();
+
+  // Verify "Create new repo" is selected by default
+  await expect(po.githubConnector.getCreateNewRepoModeButton()).toHaveClass(
+    /bg-primary/,
+  );
+
+  await po.githubConnector.fillCreateRepoName("test-new-repo");
+
+  // Wait for availability check
+  await po.page.waitForSelector("text=Repository name is available!", {
+    timeout: 5000,
+  });
+
+  // Click create repo button
+  await po.githubConnector.clickCreateRepoButton();
+
+  // Snapshot post-creation state
+  await po.githubConnector.snapshotConnectedRepo();
+
+  // Sync: capture success message
+  await po.githubConnector.clickSyncToGithubButton();
+
+  await po.githubConnector.snapshotConnectedRepo();
+  // Verify the push was received for the default branch (main)
+  await po.githubConnector.verifyPushEvent({
+    repo: "test-new-repo",
+    branch: "main",
+    operation: "create",
+  });
+});
+
+test("create and sync to new repo - custom branch", async ({ po }) => {
+  await po.setUp();
+  await po.sendPrompt("tc=basic");
+
+  await po.getTitleBarAppNameButton().click();
+  await po.githubConnector.connect();
+
+  await po.githubConnector.fillCreateRepoName("test-new-repo");
+  await po.githubConnector.fillNewRepoBranchName("new-branch");
+
+  // Click create repo button
+  await po.githubConnector.clickCreateRepoButton();
+
+  // Sync to GitHub
+  await po.githubConnector.clickSyncToGithubButton();
+
+  // Snapshot post-creation state
+  await po.githubConnector.snapshotConnectedRepo();
+
+  // Verify the push was received for the correct custom branch
+  await po.githubConnector.verifyPushEvent({
+    repo: "test-new-repo",
+    branch: "new-branch",
+    operation: "create",
+  });
+});
+
+test("disconnect from repo", async ({ po }) => {
+  await po.setUp();
+  await po.sendPrompt("tc=basic");
+
+  await po.getTitleBarAppNameButton().click();
+  await po.githubConnector.connect();
+
+  await po.githubConnector.fillCreateRepoName("test-new-repo");
+  await po.githubConnector.clickCreateRepoButton();
+
+  await po.githubConnector.clickDisconnectRepoButton();
+  await po.githubConnector.getSetupYourGitHubRepoButton().click();
+  // Make this deterministic
+  await po.githubConnector.fillCreateRepoName("[scrubbed]");
+  await po.githubConnector.snapshotSetupRepo();
+});
+
+test("create and sync to existing repo", async ({ po }) => {
+  await po.setUp();
+  await po.sendPrompt("tc=basic");
+
+  await po.getTitleBarAppNameButton().click();
+  await po.githubConnector.connect();
+
+  await po.githubConnector.getConnectToExistingRepoModeButton().click();
+
+  await po.githubConnector.selectRepo("testuser/existing-app");
+  await po.githubConnector.selectBranch("main");
+  await po.githubConnector.clickConnectToRepoButton();
+
+  await po.githubConnector.snapshotConnectedRepo();
+});
+
+test("create and sync to existing repo - custom branch", async ({ po }) => {
+  // Clear any previous push events
+  await po.githubConnector.clearPushEvents();
+
+  await po.setUp();
+  await po.sendPrompt("tc=basic");
+
+  await po.getTitleBarAppNameButton().click();
+  await po.githubConnector.connect();
+
+  await po.githubConnector.getConnectToExistingRepoModeButton().click();
+
+  await po.githubConnector.selectRepo("testuser/existing-app");
+  await po.githubConnector.selectCustomBranch("new-branch");
+  await po.githubConnector.clickConnectToRepoButton();
+
+  // Sync to GitHub to trigger a push
+  await po.githubConnector.clickSyncToGithubButton();
+  await po.githubConnector.snapshotConnectedRepo();
+  // Verify the push was received for the correct custom branch
+  await po.githubConnector.verifyPushEvent({
+    repo: "existing-app",
+    branch: "new-branch",
+    operation: "create",
+  });
+});