chore(deps): upgrade next to 16.3.0 and clean up the TypeScript toolchain (#6235)

Bumps next, @next/env and the @next/swc-* optional deps to 16.3.0 across the
root overrides, apps/sim, apps/docs and packages/emcn.

Two config notes worth keeping:

- `experimental.turbopackFileSystemCacheForBuild`'s default flipped false ->
  true for stable in 16.3.0, so our explicit `false` is now load-bearing rather
  than defensive. Without it this bump would have silently re-enabled a build
  cache measured 3.2x slower on this codebase (#6078). Comment updated to say so.
- `experimental.useTypeScriptCli: true` is now pinned. TypeScript 7 ships no
  JavaScript compiler API until 7.1, so Next's default checker cannot run and
  needs the project-local `tsc` CLI instead. 16.2.12 was silently skipping
  build-time type checking entirely because it detected @typescript/native-preview
  and short-circuited the stage ("Finished TypeScript in 138ms"); pinning the flag
  keeps that from drifting back.

TypeScript toolchain cleanup that the upgrade makes possible:

- Drop @typescript/native-preview from apps/sim and apps/docs. It was the
  pre-release channel for TS 7 and is superseded by typescript@7 (nightlies now
  ship as typescript@next), and its presence is what suppressed build type checks.
- Align packages/browser-protocol and packages/terminal-protocol from
  typescript ^5.7.3 to ^7.0.2 so every workspace is on one compiler version.

apps/sim keeps @typescript/typescript6 as a production dependency: the function
sandbox at app/api/function/execute dynamically imports the TS 6 compiler API to
transpile user code, and TS 7 has no API to replace it yet.

Build and dev were benchmarked 3x per version on a byte-identical tree; the
upgrade is performance-neutral (build median 100s -> 99s, dev:full warm 10s -> 9s).

Author: waleedlatif1

apps/docs/package.json

@@ -31,7 +31,7 @@
     "fumadocs-openapi": "10.8.1",
     "fumadocs-ui": "16.8.5",
     "lucide-react": "^0.511.0",
-    "next": "16.2.12",
+    "next": "16.3.0",
     "next-themes": "^0.4.6",
     "react": "19.2.4",
     "react-dom": "19.2.4",
@@ -50,7 +50,6 @@
     "@types/node": "24.2.1",
     "@types/react": "^19.1.2",
     "@types/react-dom": "^19.0.4",
-    "@typescript/native-preview": "7.0.0-dev.20260707.2",
     "postcss": "^8.5.3",
     "tailwindcss": "^4.0.12",
     "typescript": "^7.0.2"

apps/sim/next.config.ts

@@ -219,12 +219,17 @@ const nextConfig: NextConfig = {
      * it lives. Restoring across commits is separately undocumented-as-supported
      * (vercel/next.js#87283 reports stale HTML from a cache built elsewhere).
      *
-     * Pinned explicitly rather than left to the Next default: upstream already
-     * flips this default to true in canary/preview builds (vercel/next.js#94616),
-     * so relying on the default would let a version bump silently re-enable a
-     * config we measured as harmful.
+     * The explicit pin is load-bearing: 16.3.0 flipped this default to true for
+     * stable (vercel/next.js#94616), so dropping it re-enables the slower cache.
      */
     turbopackFileSystemCacheForBuild: false,
+    /**
+     * TypeScript 7 ships no JavaScript compiler API until 7.1, so Next's default
+     * checker cannot load it — this shells out to the project-local `tsc` instead.
+     * Pinned because the failure mode is not slower type checking but none at all:
+     * 16.2.12 skipped the stage silently in 138ms.
+     */
+    useTypeScriptCli: true,
     preloadEntriesOnStart: false,
     /**
      * Under Turbopack this is not a no-op: the list feeds

apps/sim/package.json

@@ -193,7 +193,7 @@
     "mongodb": "6.19.0",
     "mysql2": "3.14.3",
     "neo4j-driver": "6.0.1",
-    "next": "16.2.12",
+    "next": "16.3.0",
     "next-mdx-remote": "^6.0.0",
     "next-runtime-env": "3.3.0",
     "next-themes": "^0.4.6",
@@ -260,7 +260,6 @@
     "@types/react-dom": "^19",
     "@types/ssh2": "^1.15.5",
     "@types/three": "0.177.0",
-    "@typescript/native-preview": "7.0.0-dev.20260707.2",
     "@vitejs/plugin-react": "^4.3.4",
     "@vitest/coverage-v8": "^4.1.0",
     "postcss": "^8",

bun.lock

@@ -79,8 +79,8 @@
   "overrides": {
     "react": "19.2.4",
     "react-dom": "19.2.4",
-    "next": "16.2.12",
-    "@next/env": "16.2.12",
+    "next": "16.3.0",
+    "@next/env": "16.3.0",
     "drizzle-orm": "^0.45.2",
     "postgres": "^3.4.5",
     "minimatch": "^10.2.5",
@@ -89,10 +89,10 @@
     "e2b": "^2.36.1"
   },
   "optionalDependencies": {
-    "@next/swc-darwin-arm64": "16.2.12",
-    "@next/swc-darwin-x64": "16.2.12",
-    "@next/swc-linux-arm64-gnu": "16.2.12",
-    "@next/swc-linux-x64-gnu": "16.2.12"
+    "@next/swc-darwin-arm64": "16.3.0",
+    "@next/swc-darwin-x64": "16.3.0",
+    "@next/swc-linux-arm64-gnu": "16.3.0",
+    "@next/swc-linux-x64-gnu": "16.3.0"
   },
   "devDependencies": {
     "@biomejs/biome": "2.0.0-beta.5",

package.json

@@ -26,6 +26,6 @@
   "devDependencies": {
     "@sim/tsconfig": "workspace:*",
     "@types/node": "24.2.1",
-    "typescript": "^5.7.3"
+    "typescript": "^7.0.2"
   }
 }

packages/browser-protocol/package.json

@@ -84,7 +84,7 @@
     "framer-motion": "^12.5.0",
     "input-otp": "^1.4.2",
     "lucide-react": "^0.511.0",
-    "next": "16.2.12",
+    "next": "16.3.0",
     "prismjs": "^1.30.0",
     "react": "19.2.4",
     "react-dom": "19.2.4",

packages/emcn/package.json

@@ -26,6 +26,6 @@
   "devDependencies": {
     "@sim/tsconfig": "workspace:*",
     "@types/node": "24.2.1",
-    "typescript": "^5.7.3"
+    "typescript": "^7.0.2"
   }
 }