fix(chat): drop unsafe toSorted, keep code-split + Map lookup

toSorted (ES2023) is not polyfilled by SWC and crashes iOS15/Safari<16 in
client bundles, so revert use-skill-auto-mention to the non-mutating
[...arr].sort() it had. The code-split of MothershipView and the first-match
Map lookup in prompt-editor are unaffected. Tighten the sim-imports code-split
note to state webpack *can* retain the barrel edge (removing the dead re-export
is the guaranteed fix).

Author: waleedlatif1

.claude/rules/sim-imports.md

@@ -33,7 +33,7 @@ import { Dashboard } from '@/app/workspace/[workspaceId]/logs/components/dashboa
 
 ## Code-splitting through barrels
 
-When you `lazy(() => import(...))` a component to keep it out of a route's initial bundle, import the **deep module path** (`./components/foo/foo`), never the barrel — and **delete the now-dead barrel re-export** of that component. This app has no `"sideEffects": false` in `apps/sim/package.json`, so webpack keeps a barrel's re-export edge to the heavy module whenever any sibling still imports that barrel. A leftover `export { Foo } from './foo'` line therefore drags `Foo` (and its transitive deps) back into the initial chunk and silently defeats the split. Verify the split with a production bundle diff, not just by eyeballing the `lazy()` call.
+When you `lazy(() => import(...))` a component to keep it out of a route's initial bundle, import the **deep module path** (`./components/foo/foo`), never the barrel — and **delete the now-dead barrel re-export** of that component. This app has no `"sideEffects": false` in `apps/sim/package.json`, so when any sibling still imports that barrel, webpack can conservatively keep the barrel's re-export edge to the heavy module. A leftover `export { Foo } from './foo'` line can therefore drag `Foo` (and its transitive deps) back into the initial chunk and silently defeat the split. Removing the dead re-export is the guaranteed fix; verify with a production bundle diff, not by eyeballing the `lazy()` call.
 
 ```typescript
 // ✓ Good — deep lazy import + no barrel edge left behind

apps/sim/app/workspace/[workspaceId]/home/components/user-input/hooks/use-skill-auto-mention.ts

@@ -176,7 +176,7 @@ export function useSkillAutoMention({ skills, setSelectedContexts }: UseSkillAut
       // descending so earlier replacements don't shift later indices; the
       // sentinel is one code unit wide like '/'.
       let result = text
-      for (const idx of slashIndices.toSorted((a, b) => b - a)) {
+      for (const idx of [...slashIndices].sort((a, b) => b - a)) {
         result = result.slice(0, idx) + SKILL_CHIP_TRIGGER + result.slice(idx + 1)
       }
       return result