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/components/connections-badge.tsx

@@ -0,0 +1,94 @@
+'use client'
+
+import { useState, useEffect } from 'react'
+import { Sparkles } from 'lucide-react'
+import { cn } from '@/lib/utils'
+import { useLanguage } from '@/lib/i18n/LanguageProvider'
+
+interface ConnectionsBadgeProps {
+  noteId: string
+  onClick?: () => void
+  className?: string
+}
+
+interface ConnectionData {
+  noteId: string
+  title: string | null
+  content: string
+  createdAt: Date
+  similarity: number
+  daysApart: number
+}
+
+interface ConnectionsResponse {
+  connections: ConnectionData[]
+  pagination: {
+    total: number
+    page: number
+    limit: number
+    totalPages: number
+    hasNext: boolean
+    hasPrev: boolean
+  }
+}
+
+export function ConnectionsBadge({ noteId, onClick, className }: ConnectionsBadgeProps) {
+  const { t } = useLanguage()
+  const [connectionCount, setConnectionCount] = useState<number>(0)
+  const [isLoading, setIsLoading] = useState(false)
+  const [isHovered, setIsHovered] = useState(false)
+
+  useEffect(() => {
+    const fetchConnections = async () => {
+      setIsLoading(true)
+      try {
+        const res = await fetch(`/api/ai/echo/connections?noteId=${noteId}&limit=1`)
+        if (!res.ok) {
+          throw new Error('Failed to fetch connections')
+        }
+
+        const data: ConnectionsResponse = await res.json()
+        setConnectionCount(data.pagination.total || 0)
+      } catch (error) {
+        console.error('[ConnectionsBadge] Failed to fetch connections:', error)
+        setConnectionCount(0)
+      } finally {
+        setIsLoading(false)
+      }
+    }
+
+    fetchConnections()
+  }, [noteId])
+
+  // Don't render if no connections or still loading
+  if (connectionCount === 0 || isLoading) {
+    return null
+  }
+
+  const plural = connectionCount > 1 ? 's' : ''
+  const badgeText = t('memoryEcho.connectionsBadge', { count: connectionCount, plural })
+
+  return (
+    <div
+      className={cn(
+        'px-1.5 py-0.5 rounded',
+        'bg-amber-100 dark:bg-amber-900/30',
+        'text-amber-700 dark:text-amber-400',
+        'text-[10px] font-medium',
+        'border border-amber-200 dark:border-amber-800',
+        'cursor-pointer',
+        'transition-all duration-150 ease-out',
+        'hover:bg-amber-200 dark:hover:bg-amber-800/50',
+        isHovered && 'scale-105',
+        className
+      )}
+      onClick={onClick}
+      onMouseEnter={() => setIsHovered(true)}
+      onMouseLeave={() => setIsHovered(false)}
+      title={badgeText}
+    >
+      <Sparkles className="h-2.5 w-2.5 inline-block mr-1" />
+      {badgeText}
+    </div>
+  )
+}