fix(config): drop three dead next.config entries and correct two stale comments (#6076)

`optimizePackageImports` is not a no-op under Turbopack, despite what the
Next docs say. In 16.2.11 the list feeds `side_effect_free_packages` and is
force-appended to `transpiledPackages`, which also removes each entry from
the server externals set — and it overrides each listed package's own
`sideEffects` declaration rather than hinting. So a stale entry is not free.

Two entries are provably dead: `lodash` has zero import sites repo-wide and
is not a dependency of any package here (Next also already applies a
`lodash -> lodash/{{member}}` modularizeImports rule unconditionally), and
`@radix-ui/react-accordion`'s only occurrence in the repo was this line.

`prettier` in `transpilePackages` is dead for a different reason: nothing
imports it, it is in no package.json, and the repo formats with Biome. It
sits in node_modules only as a transitive dep. `transpilePackages` matches
on modules already in the graph, so this entry was transpiling nothing.

Also corrects two comments that claimed more than the code does:
- the `.map` header rule said it blocks access to sourcemaps; it only sets
  `noindex` and a TTL. The maps ship publicly in the production image.
- the minimal-registry comment's numbers were badly stale (~247 tools ->
  4,351; ~2,074 modules -> ~5,907) and its framing wrong: blocks are not a
  co-equal cost, and the tool registry is reached through four redundant
  client edges, not just providers/utils — which is why cutting only that
  one edge buys a single module.

No behavior change intended: the removed entries were inert. Kept `zod`,
`reactflow`, `framer-motion`, and `streamdown`, which are real barrels with
real import sites — removing those changes tree-shaking hints and needs a
bundle-size measurement, not a guess.

apps/sim/next.config.ts

@@ -11,12 +11,22 @@ import {
 /**
  * Dev-only escape hatch: when `SIM_DEV_MINIMAL_REGISTRY=1` (`bun run dev:minimal`),
  * swap the heavy block and tool registries for tiny curated variants via a
- * Turbopack/webpack resolve alias. The shared workspace layout drags the
- * ~247-tool registry (~2,074 modules) into every route via providers/utils →
- * tools/params, and the editor/executor pull all ~268 block configs; aliasing
- * both to minimal variants stops Turbopack from compiling those graphs, cutting
- * dev compile-time RAM (e.g. /logs ~16GB → ~5GB, 4.9min → ~15s). Only the
- * curated core blocks/tools work in this mode. Never enabled in production.
+ * Turbopack/webpack resolve alias.
+ *
+ * The tool registry (4,351 entries across 261 service dirs) pulls ~5,907 modules
+ * and is 68-78% of every workspace route's module graph; aliasing it away takes
+ * `app/workspace/layout.tsx` from 5,916 modules to 1,255. Blocks are NOT a
+ * co-equal cost - `blocks/registry-maps` alone accounts for ~349 modules and
+ * mostly rides in behind the tool registry.
+ *
+ * It is reached through ONE choke point (`tools/utils.ts` → `@/tools/registry`)
+ * fed by four redundant client-reachable edges: providers/utils → tools/params,
+ * lib/workflows/blocks/block-outputs, lib/workflows/sanitization/validation, and
+ * serializer/index. All four must be severed for any of them to matter, which is
+ * why cutting only the providers/utils edge buys a single module.
+ *
+ * Only the curated core blocks/tools work in this mode. Never enabled in
+ * production - the minimal variants genuinely drop ~250 services and ~280 blocks.
  */
 const useMinimalRegistry = isDev && process.env.SIM_DEV_MINIMAL_REGISTRY === '1'
 const minimalRegistryAlias: Record<string, string> = useMinimalRegistry
@@ -150,8 +160,15 @@ const nextConfig: NextConfig = {
      */
     turbopackFileSystemCacheForBuild: process.env.NEXT_TURBOPACK_BUILD_CACHE === '1',
     preloadEntriesOnStart: false,
+    /**
+     * Under Turbopack this is not a no-op: the list feeds
+     * `side_effect_free_packages` and is force-appended to `transpiledPackages`,
+     * which also removes each entry from the server externals set. Entries here
+     * must be real barrel packages that are actually imported - a stale entry
+     * costs transform work and overrides that package's own `sideEffects`
+     * declaration.
+     */
     optimizePackageImports: [
-      'lodash',
       'framer-motion',
       'reactflow',
       '@radix-ui/react-dialog',
@@ -159,7 +176,6 @@ const nextConfig: NextConfig = {
       '@radix-ui/react-popover',
       '@radix-ui/react-select',
       '@radix-ui/react-tabs',
-      '@radix-ui/react-accordion',
       '@radix-ui/react-checkbox',
       '@radix-ui/react-switch',
       '@radix-ui/react-slider',
@@ -186,7 +202,6 @@ const nextConfig: NextConfig = {
     ],
   }),
   transpilePackages: [
-    'prettier',
     '@react-email/components',
     '@react-email/render',
     '@t3-oss/env-nextjs',
@@ -259,7 +274,10 @@ const nextConfig: NextConfig = {
           },
         ],
       },
-      // Block access to sourcemap files (defense in depth). The trailing
+      // Keeps sourcemap files out of search indexes. This does NOT block
+      // access to them - `productionBrowserSourceMaps` is on and the `.map`
+      // files ship publicly in the production image; nothing here restricts
+      // who can fetch one. The trailing
       // `$` this rule previously ended with is not a regex anchor in Next's
       // `source` matcher (path-to-regexp syntax, not raw regex) - it matched
       // a literal `$` character, so this rule never actually fired against