feat: integrate OIDC token exchange in GitHub Action

- Add setupGitHubInstallationToken utility for OIDC token generation
- Implement automatic token exchange with Pullfrog API endpoint
- Add support for multiple authentication methods (input, env, OIDC)
- Create setup utilities for test repository management
- Update action entry point to handle new token flow
- Add environment variable documentation for API key
- Remove large bundled dependencies and optimize build
- Support both development and production token workflows

utils/setup.ts

@@ -0,0 +1,51 @@
+import { execSync } from "node:child_process";
+import { existsSync, rmSync } from "node:fs";
+
+export interface SetupOptions {
+  tempDir: string;
+  repoUrl?: string;
+  forceClean?: boolean;
+}
+
+/**
+ * Setup the test repository for running actions
+ */
+export function setupTestRepo(options: SetupOptions): void {
+  const {
+    tempDir,
+    repoUrl = "git@github.com:pullfrogai/scratch.git",
+    forceClean = false,
+  } = options;
+
+  // Handle existing temp directory
+  if (existsSync(tempDir)) {
+    if (forceClean) {
+      console.log("🗑️  Removing existing .temp directory...");
+      rmSync(tempDir, { recursive: true, force: true });
+
+      // Clone the repository
+      console.log("📦 Cloning pullfrogai/scratch into .temp...");
+      execSync(`git clone ${repoUrl} ${tempDir}`, { stdio: "inherit" });
+    } else {
+      console.log("📦 Resetting existing .temp repository...");
+      execSync("git reset --hard HEAD && git clean -fd", {
+        cwd: tempDir,
+        stdio: "inherit",
+      });
+    }
+  } else {
+    console.log("📦 Cloning pullfrogai/scratch into .temp...");
+    execSync(`git clone ${repoUrl} ${tempDir}`, { stdio: "inherit" });
+  }
+}
+
+/**
+ * Build the action bundles
+ */
+export function buildAction(actionPath: string): void {
+  console.log("🔨 Building fresh bundles with esbuild...");
+  execSync("node esbuild.config.js", {
+    cwd: actionPath,
+    stdio: "inherit",
+  });
+}