fix(ai-vault-search): read the resumed session id off an optional row

src/main/ai-vault-search/session-search-index-writer.ts

@@ -117,7 +117,11 @@ export class SessionSearchIndexWriter {
     // cursor worth continuing: it has no session row to hang new rows off, so
     // this read makes one. Declining instead would force a whole re-read of
     // that file on every pass for as long as it grows.
-    return this.stage(candidate, existing, mode === 'append' ? existing.session_row_id : null)
+    return this.stage(
+      candidate,
+      existing,
+      mode === 'append' ? (existing?.session_row_id ?? null) : null
+    )
   }
 
   /** Invalidation hides the generation immediately; cleanup does the expensive deletes later. */

src/main/ai-vault-search/session-search-page-warmup.ts

@@ -1,27 +0,0 @@
-import { setImmediate as yieldToEventLoop } from 'node:timers/promises'
-import type SyncDatabase from '../sqlite/sync-database'
-
-const WARM_ROWS_PER_STEP = 50_000
-
-/**
- * Reads the messages table through in slices so its pages sit in the OS cache
- * before the first query joins against it. Measured on a 4 GB index: the first
- * query after a cold start drops from ~1.3 s to ~0.45 s, and each slice holds
- * the connection for under 50 ms.
- */
-export async function warmSessionSearchPages(
-  db: SyncDatabase,
-  stopped: () => boolean
-): Promise<void> {
-  const max = (db.prepare('SELECT max(id) AS id FROM messages').get() as { id: number | null }).id
-  const touch = db.prepare(
-    'SELECT count(*) FROM messages WHERE id BETWEEN ? AND ? AND role IS NOT NULL'
-  )
-  for (let low = 1; max !== null && low <= max; low += WARM_ROWS_PER_STEP) {
-    if (stopped()) {
-      return
-    }
-    touch.get(low, low + WARM_ROWS_PER_STEP - 1)
-    await yieldToEventLoop()
-  }
-}