feat: rename keep-notes to memento-note, migrate to PostgreSQL, fix MCP bugs

- Rename directory keep-notes -> memento-note with all code references
- Prisma: SQLite -> PostgreSQL (both app and MCP server schemas)
- Sync MCP schema with main app (add missing fields, relations, indexes)
- Delete 17 SQLite migrations (clean slate for PostgreSQL)
- Remove SQLite dependencies (@libsql/client, better-sqlite3, etc.)
- Fix MCP server: hardcoded Windows DB paths -> DATABASE_URL env var
- Fix MCP server: .dockerignore excluded index-sse.js (SSE mode broken)
- MCP Dockerfile: node:20 -> node:22
- Docker Compose: add postgres service, remove SQLite volume
- Generate favicon.ico, icon-192.png, icon-512.png, apple-icon.png
- Update layout.tsx icons and manifest.json for PNG icons
- Update all .env files for PostgreSQL
- Rewrite README.md with updated sections
- Remove mcp-server/node_modules and prisma/client-generated from git tracking

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

memento-note/app/actions/semantic-search.ts

@@ -0,0 +1,63 @@
+'use server'
+
+import { semanticSearchService, SearchResult } from '@/lib/ai/services/semantic-search.service'
+
+export interface SemanticSearchResponse {
+  results: SearchResult[]
+  query: string
+  totalResults: number
+}
+
+/**
+ * Perform hybrid semantic + keyword search
+ * Supports contextual search within notebook (IA5)
+ */
+export async function semanticSearch(
+  query: string,
+  options?: {
+    limit?: number
+    threshold?: number
+    notebookId?: string // NEW: Filter by notebook for contextual search (IA5)
+  }
+): Promise<SemanticSearchResponse> {
+  try {
+    const results = await semanticSearchService.search(query, {
+      limit: options?.limit || 20,
+      threshold: options?.threshold || 0.6,
+      notebookId: options?.notebookId // NEW: Pass notebook filter
+    })
+
+    return {
+      results,
+      query,
+      totalResults: results.length
+    }
+  } catch (error) {
+    console.error('Error in semantic search action:', error)
+    throw error
+  }
+}
+
+/**
+ * Index a note for semantic search (generate embedding)
+ */
+export async function indexNote(noteId: string): Promise<void> {
+  try {
+    await semanticSearchService.indexNote(noteId)
+  } catch (error) {
+    console.error('Error indexing note:', error)
+    throw error
+  }
+}
+
+/**
+ * Batch index notes (for initial setup)
+ */
+export async function batchIndexNotes(noteIds: string[]): Promise<void> {
+  try {
+    await semanticSearchService.indexBatchNotes(noteIds)
+  } catch (error) {
+    console.error('Error batch indexing notes:', error)
+    throw error
+  }
+}