ui: Sidebar Conversations Bulk Action + Improved Settings logic/UI (#25815)

* feat: WIP

* feat: Replace conversation rename flow with unified AlertDialog component

* feat: Add radio group component and consolidate title generation settings

* refactor: Remove JS Sandbox global toggle and migrate legacy user state

* chore: Formatting

* refactor: Cleanup

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

* refactor: Cleanup

* refactor: Marquee selection hook

* feat: UI improvements

* refactor: Bulk db operations

* fix: optimize bulk conversation deletion to handle ancestor chains

* refactor: remove pairedKey mechanism from settings system

* fix: remove redundant onclick handler from dialog cancel button

* chore: pin @lucide/svelte to exact version

* feat: Run JavaScript tool disabled by default

* fix: correct active conversation deletion tracking in bulk delete

* feat: improve shift-key multi-selection support in sidebar via keyboard

* refactor: Retrieve JS Tool enabling via Developer Settings

* nits: sync, dialog wording, cycle guard, and lockfile follow-ups

- Restore titleGenerationUseLLM registry entry so it syncs across devices again
- Mention fork cascade in the bulk delete confirmation dialog
- Clear newParent on cycle guard break so children never point at a deleted conversation
- Align @lucide/svelte in package-lock.json with the exact pin in package.json

---------

Co-authored-by: Pascal <admin@serveurperso.com>

tools/ui/src/lib/components/app/dialogs/DialogConversationSelection.svelte

@@ -37,9 +37,9 @@
 
 <Dialog.Root bind:open>
 	<Dialog.Portal>
-		<Dialog.Overlay class="z-[1000000]" />
+		<Dialog.Overlay class="z-1000000" />
 
-		<Dialog.Content class="z-[1000001] max-w-2xl">
+		<Dialog.Content class="z-1000001 max-w-2xl">
 			<Dialog.Header>
 				<Dialog.Title>
 					Select Conversations to {mode === 'export' ? 'Export' : 'Import'}
@@ -58,6 +58,7 @@
 
 			<ConversationSelection
 				bind:this={conversationSelectionRef}
+				isOpen={open}
 				{conversations}
 				{messageCountMap}
 				{mode}