fix: brainstorm infinite loop, ghost cursor, embedding ::vector cast, semantic search, billing stats, usage meter accordion

- Fix useBrainstormSocket: stable guestId via useRef, remove setState in cleanup
- Fix GhostCursor: direct DOM manipulation via refs, no useState re-renders
- Fix all SQL embedding queries: add ::vector cast on text columns
- Fix embedding truncation to 15000 chars (under 8192 token limit)
- Fix NoteEmbedding INSERT: remove non-existent updatedAt column
- Fix billing page: show all quota stats in grid instead of single metric
- Fix usage meter: accordion expand/collapse, per-feature detail
- Fix semantic search: rebuild 103 note embeddings, ::vector cast on vectorSearch
- Fix brainstorm expand/manual-idea/create: ::vector cast on embedding SQL

memento-note/lib/ai/services/embedding.service.ts

@@ -15,16 +15,24 @@ export interface EmbeddingResult {
 
 export class EmbeddingService {
   private readonly EMBEDDING_DIMENSION = 1536
+  private readonly MAX_CHARS = 15000
+
+  private truncateForEmbedding(text: string): string {
+    if (text.length <= this.MAX_CHARS) return text
+    return text.slice(0, this.MAX_CHARS)
+  }
 
   async generateEmbedding(text: string): Promise<EmbeddingResult> {
     if (!text || text.trim().length === 0) {
       throw new Error('Cannot generate embedding for empty text')
     }
 
+    const truncated = this.truncateForEmbedding(text)
+
     try {
       const config = await getSystemConfig()
       const embedding = await withAiProviderFallback('embedding', config, (provider) =>
-        provider.getEmbeddings(text)
+        provider.getEmbeddings(truncated)
       )
 
       return {
@@ -41,7 +49,7 @@ export class EmbeddingService {
   async generateBatchEmbeddings(texts: string[]): Promise<EmbeddingResult[]> {
     if (!texts || texts.length === 0) return []
 
-    const validTexts = texts.filter(t => t && t.trim().length > 0)
+    const validTexts = texts.filter(t => t && t.trim().length > 0).map(t => this.truncateForEmbedding(t))
     if (validTexts.length === 0) return []
 
     try {

memento-note/lib/ai/services/memory-echo.service.ts

@@ -77,14 +77,14 @@ export class MemoryEchoService {
       for (const note of notesWithoutEmbeddings) {
         if (!note.content || note.content.trim().length === 0) continue
         try {
-          const embedding = await provider.getEmbeddings(note.content)
+          const embedding = await provider.getEmbeddings(note.content.slice(0, 15000))
           if (embedding && embedding.length > 0) {
             const vecStr = `[${embedding.join(',')}]`
             await prisma.$executeRawUnsafe(
-              `INSERT INTO "NoteEmbedding" ("id", "noteId", "embedding", "createdAt", "updatedAt")
-               VALUES (gen_random_uuid(), $1, $2::vector, now(), now())
+              `INSERT INTO "NoteEmbedding" ("id", "noteId", "embedding", "createdAt")
+               VALUES (gen_random_uuid(), $1, $2::vector, now())
                ON CONFLICT ("noteId")
-               DO UPDATE SET "embedding" = $2::vector, "updatedAt" = now()`,
+               DO UPDATE SET "embedding" = $2::vector`,
               note.id,
               vecStr
             )

memento-note/lib/ai/services/paragraph-refactor.service.ts

@@ -286,11 +286,15 @@ Only return the translated text, nothing else.`,
 Keep the explanation clear, educational, and concise.`
     }
 
+    const systemSuffix = mode === 'explain'
+      ? `CRITICAL: Respond ONLY with your explanation in ${language}. No meta-commentary, no English. Format strictly as ${format === 'html' ? 'HTML tags' : 'Markdown'}.`
+      : `CRITICAL: Respond ONLY with the refactored text in ${language}. No explanations, no meta-commentary, no English. Format strictly as ${format === 'html' ? 'HTML tags' : 'Markdown'}.`
+
     return `${instructions[mode]}
 
 ${content}
 
-CRITICAL: Respond ONLY with the refactored text in ${language}. No explanations, no meta-commentary, no English. Format strictly as ${format === 'html' ? 'HTML tags' : 'Markdown'}.`
+${systemSuffix}`
   }
 
   /**

memento-note/lib/ai/services/semantic-search.service.ts

@@ -235,15 +235,15 @@ export class SemanticSearchService {
 
     const rows: Array<{ noteId: string; similarity: number }> = await prisma.$queryRawUnsafe(
       `SELECT n.id AS "noteId",
-              1 - (e."embedding" <=> ${vecParam}) AS similarity
+              1 - (e."embedding"::vector <=> ${vecParam}) AS similarity
        FROM "Note" n
        INNER JOIN "NoteEmbedding" e ON e."noteId" = n.id
        WHERE n."trashedAt" IS NULL
          AND n."isArchived" = false
          ${userClause}
          ${notebookClause}
-         AND 1 - (e."embedding" <=> ${vecParam}) >= ${thresholdParam}
-       ORDER BY e."embedding" <=> ${vecParam} ASC
+         AND 1 - (e."embedding"::vector <=> ${vecParam}) >= ${thresholdParam}
+       ORDER BY e."embedding"::vector <=> ${vecParam} ASC
        LIMIT ${limitParam}`,
       ...params
     )
@@ -356,10 +356,10 @@ export class SemanticSearchService {
       const vecStr = embeddingService.toVectorString(embedding)
 
       await prisma.$queryRawUnsafe(
-        `INSERT INTO "NoteEmbedding" ("id", "noteId", "embedding", "createdAt", "updatedAt")
-         VALUES (gen_random_uuid(), $1, $2::vector, now(), now())
+        `INSERT INTO "NoteEmbedding" ("id", "noteId", "embedding", "createdAt")
+         VALUES (gen_random_uuid(), $1, $2::vector, now())
          ON CONFLICT ("noteId")
-         DO UPDATE SET "embedding" = $2::vector, "updatedAt" = now()`,
+         DO UPDATE SET "embedding" = $2::vector`,
         noteId,
         vecStr
       )
@@ -427,7 +427,7 @@ export class SemanticSearchService {
         AND n."trashedAt" IS NULL
         AND n."userId" = $3
         ${noteFilter}
-      ORDER BY dc."embedding" <=> $1::vector
+      ORDER BY dc."embedding"::vector <=> $1::vector
       LIMIT $2`,
       ...params
     ) as any[]