modules/admin: fix migration page polling and scroll behavior

- Change getStatus from query to command to bypass caching for real-time polling
- Only auto-scroll logs when user is already at bottom (preserves scroll position)
- Update misleading comment about polling behavior

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: aster-void

src/lib/data/private/migration.remote.ts

@@ -1,4 +1,4 @@
-import { command, query } from "$app/server";
+import { command } from "$app/server";
 import { requireUtCodeMember } from "$lib/server/database/auth.server";
 import {
   startDataMigration,
@@ -13,7 +13,8 @@ export const start = command(async (): Promise<{ started: boolean; message: stri
   return startDataMigration();
 });
 
-export const getStatus = query(async (): Promise<MigrationState> => {
+// Use command instead of query to bypass caching for real-time polling
+export const getStatus = command(async (): Promise<MigrationState> => {
   await requireUtCodeMember();
   return getMigrationState();
 });

src/routes/(admin)/admin/migrate/+page.svelte

@@ -21,10 +21,15 @@
 	const isDisabled = $derived.by(() => isStarting || isRunning);
 
 	async function fetchStatus() {
+		// Check if user is at bottom before fetch
+		const wasAtBottom = logsContainer
+			? logsContainer.scrollHeight - logsContainer.scrollTop <= logsContainer.clientHeight + 10
+			: true;
+
 		migrationState = await getStatus();
 
-		// Auto-scroll logs to bottom
-		if (logsContainer) {
+		// Only auto-scroll if user was already at bottom
+		if (logsContainer && wasAtBottom) {
 			logsContainer.scrollTop = logsContainer.scrollHeight;
 		}
 	}
@@ -74,11 +79,9 @@
 		}
 	}
 
-	// Poll every 1s while running, cleanup on unmount
+	// Poll every 1s to keep status in sync, cleanup on unmount
 	$effect(() => {
 		fetchStatus().catch(console.error);
-
-		// Always poll every 1s to catch running migrations
 		pollInterval = setInterval(fetchStatus, 1000);
 
 		return () => {