feat(FN-1318): rename CLI binary artifacts from kb to fn

- Update CLI build and runtime paths to emit and reference fn-named binaries across default and cross-target builds
- Adjust Bun binary bootstrap stubs and native patch temp/symlink prefixes to use fn naming consistently
- Update CI, release, and test-release workflows to validate and collect fn-prefixed artifacts
- Align CLI build and package config tests with fn binary expectations and add a patch changeset for @gsxdsm/fusion

packages/cli/src/__tests__/build-exe-cross.test.ts

@@ -21,7 +21,7 @@ const SUPPORTED_TARGETS = [
 function expectedBinaryName(target: string): string {
   const suffix = target.replace(/^bun-/, "");
   const isWindows = target.includes("windows");
-  return `kb-${suffix}${isWindows ? ".exe" : ""}`;
+  return `fn-${suffix}${isWindows ? ".exe" : ""}`;
 }
 
 /**
@@ -44,8 +44,8 @@ describe("build-exe-cross: single target", () => {
     });
   }, 180_000);
 
-  it("produces dist/kb-linux-x64", () => {
-    const bin = join(distDir, "kb-linux-x64");
+  it("produces dist/fn-linux-x64", () => {
+    const bin = join(distDir, "fn-linux-x64");
     expect(existsSync(bin)).toBe(true);
     expect(statSync(bin).size).toBeGreaterThan(0);
   });
@@ -64,8 +64,8 @@ describe("build-exe-cross: windows target has .exe extension", () => {
     });
   }, 180_000);
 
-  it("produces dist/kb-windows-x64.exe", () => {
-    const bin = join(distDir, "kb-windows-x64.exe");
+  it("produces dist/fn-windows-x64.exe", () => {
+    const bin = join(distDir, "fn-windows-x64.exe");
     expect(existsSync(bin)).toBe(true);
     expect(statSync(bin).size).toBeGreaterThan(0);
   });
@@ -143,8 +143,8 @@ describe("build-exe-cross: default (no args) backward compatibility", () => {
     });
   }, 180_000);
 
-  it("produces dist/kb (no platform suffix)", () => {
-    const defaultName = process.platform === "win32" ? "kb.exe" : "kb";
+  it("produces dist/fn (no platform suffix)", () => {
+    const defaultName = process.platform === "win32" ? "fn.exe" : "fn";
     const bin = join(distDir, defaultName);
     expect(existsSync(bin)).toBe(true);
     expect(statSync(bin).size).toBeGreaterThan(0);

packages/cli/src/__tests__/build-exe.test.ts

@@ -6,8 +6,8 @@ import { mkdtempSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 
 const cliRoot = join(import.meta.dirname!, "..", "..");
-const outBinary = join(cliRoot, "dist", process.platform === "win32" ? "kb.exe" : "kb");
-const binaryName = process.platform === "win32" ? "kb.exe" : "kb";
+const outBinary = join(cliRoot, "dist", process.platform === "win32" ? "fn.exe" : "fn");
+const binaryName = process.platform === "win32" ? "fn.exe" : "fn";
 const clientDir = join(cliRoot, "dist", "client");
 const runtimeDir = join(cliRoot, "dist", "runtime");
 
@@ -16,7 +16,7 @@ const runtimeDir = join(cliRoot, "dist", "runtime");
  * and runtime/ assets — no package.json. Returns the dir path and a cleanup function.
  */
 function createIsolatedDir(): { dir: string; binary: string; cleanup: () => void } {
-  const dir = mkdtempSync(join(tmpdir(), "kb-iso-"));
+  const dir = mkdtempSync(join(tmpdir(), "fn-iso-"));
   cpSync(outBinary, join(dir, binaryName), { recursive: true });
   cpSync(clientDir, join(dir, "client"), { recursive: true });
   // Copy runtime native assets alongside binary

packages/cli/src/__tests__/ci-workflow.test.ts

@@ -51,7 +51,7 @@ describe("CI workflow (.github/workflows/ci.yml)", () => {
   });
 
   it("verifies binary exists after build", () => {
-    expect(content).toContain("test -f packages/cli/dist/kb");
+    expect(content).toContain("test -f packages/cli/dist/fn");
   });
 
   it("includes pnpm test step", () => {

packages/cli/src/__tests__/package-config.test.ts

@@ -37,12 +37,12 @@ describe("CLI package.json publishing config", () => {
 
   it("does not include bare 'dist' entry or globs that would match Bun binaries", () => {
     const bunBinaryNames = [
-      "kb",
-      "kb-linux-x64",
-      "kb-linux-arm64",
-      "kb-darwin-x64",
-      "kb-darwin-arm64",
-      "kb-windows-x64.exe",
+      "fn",
+      "fn-linux-x64",
+      "fn-linux-arm64",
+      "fn-darwin-x64",
+      "fn-darwin-arm64",
+      "fn-windows-x64.exe",
     ];
     // No bare "dist" entry that would include everything
     expect(pkg.files).not.toContain("dist");
@@ -51,8 +51,8 @@ describe("CLI package.json publishing config", () => {
       for (const bin of bunBinaryNames) {
         expect(entry).not.toBe(`dist/${bin}`);
       }
-      // No wildcard like "dist/kb*" that would match binaries
-      expect(entry).not.toMatch(/^dist\/kb/);
+      // No wildcard like "dist/fn*" that would match binaries
+      expect(entry).not.toMatch(/^dist\/fn/);
     }
   });
 

packages/cli/src/bin.ts

@@ -24,11 +24,11 @@ if (isBunBinary) {
 
   if (!existsSync(localPkg)) {
     // Write a minimal package.json to a temp dir and redirect PI_PACKAGE_DIR
-    const tmp = mkdtempSync(join(tmpdir(), "kb-pkg-"));
+    const tmp = mkdtempSync(join(tmpdir(), "fn-pkg-"));
     writeFileSync(
       join(tmp, "package.json"),
       JSON.stringify(
-        { name: "kb", version: "0.1.0", type: "module", piConfig: { name: "kb", configDir: ".fusion" } },
+        { name: "fn", version: "0.1.0", type: "module", piConfig: { name: "fn", configDir: ".fusion" } },
         null,
         2,
       ) + "\n",

packages/cli/src/runtime/native-patch.ts

@@ -8,7 +8,7 @@
  * where bundled code runs. Node-pty looks for native modules at:
  *   /$bunfs/root/prebuilds/<platform>-<arch>/pty.node
  *
- * This module creates a real directory structure at /tmp/kb-bunfs-<pid>/ that mirrors
+ * This module creates a real directory structure at /tmp/fn-bunfs-<pid>/ that mirrors
  * the expected structure, then attempts to create a symlink from /$bunfs/root to that
  * temp directory (on macOS/Linux) so node-pty can find the native assets.
  */
@@ -64,9 +64,9 @@ function cleanupStaleBunfsLinks(): void {
       if (stats.isSymbolicLink()) {
         const target = readlinkSync(bunfsRoot);
         // If the target is a temp dir that no longer exists, remove the stale link
-        if (target.includes("kb-bunfs-") && !existsSync(target)) {
+        if (target.includes("fn-bunfs-") && !existsSync(target)) {
           rmSync(bunfsRoot);
-          console.log("[kb-native-patch] Cleaned up stale /$bunfs/root symlink");
+          console.log("[fn-native-patch] Cleaned up stale /$bunfs/root symlink");
         }
       }
     }
@@ -79,7 +79,7 @@ function cleanupStaleBunfsLinks(): void {
  * Set up the native module resolution structure.
  *
  * Creates:
- *   /tmp/kb-bunfs-<pid>/kb/prebuilds/<platform>-<arch>/
+ *   /tmp/fn-bunfs-<pid>/fn/prebuilds/<platform>-<arch>/
  *     ├── pty.node
  *     └── spawn-helper (Unix only)
  *
@@ -89,7 +89,7 @@ function cleanupStaleBunfsLinks(): void {
 export function setupNativeResolution(): { success: boolean; nativeDir: string | null } {
   const nativeDir = findStagedNativeDir();
   if (!nativeDir) {
-    console.warn("[kb-native-patch] No native assets found, terminal will be unavailable");
+    console.warn("[fn-native-patch] No native assets found, terminal will be unavailable");
     return { success: false, nativeDir: null };
   }
 
@@ -102,9 +102,9 @@ export function setupNativeResolution(): { success: boolean; nativeDir: string |
   process.env.FUSION_NATIVE_ASSETS_PATH = nativeDir;
 
   // Create the fake bunfs structure
-  const tmpRoot = join(tmpdir(), `kb-bunfs-${process.pid}`);
-  const kbDir = join(tmpRoot, "kb");
-  const prebuildsDir = join(kbDir, "prebuilds");
+  const tmpRoot = join(tmpdir(), `fn-bunfs-${process.pid}`);
+  const fnDir = join(tmpRoot, "fn");
+  const prebuildsDir = join(fnDir, "prebuilds");
   const platformDir = join(prebuildsDir, basename(nativeDir));
 
   try {
@@ -138,23 +138,23 @@ export function setupNativeResolution(): { success: boolean; nativeDir: string |
           }
         }
 
-        // Create new symlink pointing to our temp kb directory
-        // We want /$bunfs/root -> /tmp/kb-bunfs-<pid>/kb
+        // Create new symlink pointing to our temp fn directory
+        // We want /$bunfs/root -> /tmp/fn-bunfs-<pid>/fn
         // So that /$bunfs/root/prebuilds/<platform>/pty.node resolves correctly
-        symlinkSync(kbDir, bunfsRoot);
+        symlinkSync(fnDir, bunfsRoot);
         bunfsSymlinkPath = bunfsRoot;
-        console.log("[kb-native-patch] Created /$bunfs/root symlink for native module resolution");
+        console.log("[fn-native-patch] Created /$bunfs/root symlink for native module resolution");
       } catch (symlinkErr) {
         // Symlink creation failed (likely permission denied) - not fatal
         // The terminal service will try alternative loading methods
-        console.log("[kb-native-patch] Could not create /$bunfs/root symlink (permissions), using fallback");
+        console.log("[fn-native-patch] Could not create /$bunfs/root symlink (permissions), using fallback");
       }
     }
 
-    console.log("[kb-native-patch] Native assets staged at:", tmpRoot);
+    console.log("[fn-native-patch] Native assets staged at:", tmpRoot);
     return { success: true, nativeDir };
   } catch (err) {
-    console.error("[kb-native-patch] Failed to setup native resolution:", err);
+    console.error("[fn-native-patch] Failed to setup native resolution:", err);
     return { success: false, nativeDir: null };
   }
 }