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/locales/zh.json

@@ -890,7 +890,7 @@
     "recentNotesUpdateFailed": "更新最近笔记设置失败"
   },
   "aiSettings": {
-    "title": "AI 设置",
+    "title": "AI",
     "description": "配置您的 AI 驱动功能和偏好设置",
     "features": "AI 功能",
     "provider": "AI 提供商",
@@ -917,7 +917,8 @@
     "autoLabeling": "标签建议",
     "autoLabelingDesc": "自动建议标签并将其应用到您的笔记",
     "noteHistory": "注释历史记录",
-    "noteHistoryDesc": "启用版本快照和从历史记录恢复"
+    "noteHistoryDesc": "启用版本快照和从历史记录恢复",
+    "titleSuggestions": "标题建议"
   },
   "general": {
     "loading": "加载中...",
@@ -1115,7 +1116,13 @@
       "languageDetection": "语言检测",
       "languageDetectionDesc": "自动检测每条笔记的语言",
       "autoLabeling": "自动标记",
-      "autoLabelingDesc": "自动建议并应用标签"
+      "autoLabelingDesc": "自动建议并应用标签",
+      "fallbackSectionTitle": "备用提供商（可选）",
+      "fallbackSectionDescription": "提供商出错时（429、5xx）自动启用。1.5 秒内重试一次。",
+      "fallbackProvider": "备用提供商",
+      "fallbackModel": "备用模型",
+      "fallbackNone": "无（已禁用）",
+      "fallbackModelPlaceholder": "例如 gpt-4o-mini"
     },
     "resend": {
       "title": "Resend（推荐）",
@@ -1173,6 +1180,8 @@
       "deleteFailed": "删除失败",
       "roleUpdateSuccess": "用户角色已更新为 {role}",
       "roleUpdateFailed": "更新角色失败",
+      "tierUpdateSuccess": "Subscription updated to {tier}",
+      "tierUpdateFailed": "Failed to update subscription",
       "demote": "降级",
       "promote": "升级",
       "confirmDelete": "确定吗？此操作无法撤销。",
@@ -1180,6 +1189,7 @@
         "name": "姓名",
         "email": "邮箱",
         "role": "角色",
+        "subscription": "Subscription",
         "createdAt": "创建时间",
         "actions": "操作"
       },
@@ -1371,7 +1381,7 @@
     "loading": "加载中..."
   },
   "dataManagement": {
-    "title": "数据管理",
+    "title": "Data",
     "toolsDescription": "维护数据库健康的工具",
     "exporting": "导出中...",
     "importing": "导入中...",
@@ -1436,7 +1446,7 @@
     "fontJetBrainsMono": "JetBrains Mono"
   },
   "generalSettings": {
-    "title": "常规设置",
+    "title": "General",
     "description": "常规应用程序设置"
   },
   "toast": {
@@ -1622,7 +1632,7 @@
     "collapse": "收起"
   },
   "mcpSettings": {
-    "title": "MCP 设置",
+    "title": "MCP",
     "description": "管理 API 密钥并配置外部工具",
     "whatIsMcp": {
       "title": "什么是 MCP？",
@@ -2211,7 +2221,9 @@
     "exportDefaultNoteTitle": "Synthesis",
     "exportOpening": "Opening…",
     "ownerBadge": "Owner",
-    "waveBadge": "Wave {wave}"
+    "waveBadge": "Wave {wave}",
+    "quotaGuest": "会话主持人已达到 AI 额度上限。请让对方升级套餐。",
+    "quotaHost": "您已达到此头脑风暴的 AI 额度上限。升级套餐以继续。"
   },
   "usageMeter": {
     "packName": "AI Discovery Pack",
@@ -2323,6 +2335,215 @@
     "checkoutSuccessBody": "欢迎使用{tier}，您的功能已解锁。",
     "subscriptionType": "subscriptionType",
     "renewalDate": "renewalDate",
-    "noRenewalDate": "—"
+    "noRenewalDate": "—",
+    "currentUsage": "当前使用量",
+    "currentPeriod": "当前周期",
+    "aiCredits": "AI 额度",
+    "used": "已使用",
+    "billing": "账单",
+    "renewal": "续订",
+    "paidPlanDesc": "您的订阅将自动续订。",
+    "businessDescription": "适合团队和产品负责人。"
+  },
+  "landing": {
+    "nav": {
+      "features": "功能",
+      "agents": "AI 智能体",
+      "brainstorm": "Brainstorm",
+      "pricing": "定价",
+      "tech": "架构",
+      "login": "登录",
+      "cta": "立即开始"
+    },
+    "hero": {
+      "badge": "由人工智能驱动",
+      "title1": "你的第二大脑，",
+      "title2": "终于获得放大。",
+      "subtitle": "Momento 不只是笔记应用。它是一个智能生态，通过 6 类 AI 智能体与前沿语义搜索，实时连接、分析并延展你的想法。",
+      "cta": "立即注册",
+      "secondary": "查看功能",
+      "memoryEcho": "Memory Echo",
+      "memoryEchoText": "「检测到与您 2024 年 3 月可持续设计项目的关联……」",
+      "brainstormLive": "Brainstorm Live",
+      "ideasGenerated": "+12 条创意已生成"
+    },
+    "features": {
+      "label": "AI 能力",
+      "title": "流畅的智能，",
+      "title2": "融入每一个字。",
+      "desc": "Momento 通过多提供商架构统筹你的想法。",
+      "f1Title": "语义搜索",
+      "f1Desc": "别再只靠关键词搜索。按概念查找。混合 Vector + FTS 引擎理解笔记背后的意图。",
+      "f2Title": "上下文 RAG 对话",
+      "f2Desc": "与你的知识对话。智能体阅读笔记、探索网络并分析文档，精准作答。",
+      "f3Title": "增强写作",
+      "f3Desc": "改写、标题建议、自动标签与摘要。AI 在后台帮你梳理思路。"
+    },
+    "agents": {
+      "label": "专业智能体",
+      "title": "把复杂工作交给它们。",
+      "desc": "6 类自主 AI 智能体，自动化研究、摘要与演示。",
+      "scraper": {
+        "title": "Scraper",
+        "desc": "抓取 URL、解析 RSS，并以智能配图方式汇总信息。"
+      },
+      "researcher": {
+        "title": "Researcher",
+        "desc": "生成复杂查询、探索网络来源并撰写结构化研究笔记。"
+      },
+      "slideGen": {
+        "title": "Slide Gen",
+        "desc": "将笔记转为专业 PowerPoint 或交互式 HTML 幻灯片。"
+      },
+      "monitor": {
+        "title": "Monitor",
+        "desc": "持续分析笔记本，发现趋势与新洞察。"
+      },
+      "diagramGen": {
+        "title": "Diagram Gen",
+        "desc": "将想法转为流畅的 Excalidraw 图表（思维导图、流程图）并自动排版。"
+      },
+      "custom": {
+        "title": "Custom",
+        "desc": "自定义角色与数据源的专属智能体。"
+      }
+    },
+    "brainstorm": {
+      "label": "思维之波",
+      "title": "实时放射状头脑风暴。",
+      "waveGeneration": {
+        "title": "波浪式生成",
+        "desc": "变体、类比，再到颠覆。AI 将初始概念推向极限。"
+      },
+      "collaboration": {
+        "title": "原生协作",
+        "desc": "AI 幽灵光标、同步头像与节点实时移动。"
+      },
+      "export": {
+        "title": "语义导出",
+        "desc": "一键将整个头脑风暴转为结构化笔记。"
+      },
+      "disruptionLabel": "颠覆",
+      "disruptionText": "模块化架构 2.0",
+      "analogyLabel": "类比",
+      "analogyText": "潮汐周期"
+    },
+    "tech": {
+      "label": "架构与提供商",
+      "title": "连接你自己的 AI 模型。",
+      "tags": {
+        "title": "Tags",
+        "desc": "可与任意模型独立配置。"
+      },
+      "embeddings": {
+        "title": "Embeddings",
+        "desc": "可与任意模型独立配置。"
+      },
+      "chatRag": {
+        "title": "Chat RAG",
+        "desc": "可与任意模型独立配置。"
+      }
+    },
+    "pricing": {
+      "label": "方案与定价",
+      "title": "选择你的放大级别。",
+      "desc": "为创意人士提供灵活选择，从个人使用到大型组织。",
+      "monthly": "月付",
+      "annual": "年付",
+      "perMonth": "/月",
+      "perMonthAnnual": "/月，按年计费",
+      "perUser": "+ 3.90€/user",
+      "perUserAnnual": "+ 2.90€/user, billed annually",
+      "popular": "最受欢迎",
+      "basic": {
+        "name": "Basic",
+        "desc": "发现 Momento 的魅力。",
+        "cta": "开始使用",
+        "feature0": "最多 100 条笔记",
+        "feature1": "3 个笔记本",
+        "feature2": "50 AI 积分（终身）",
+        "feature3": "语义搜索",
+        "feature4": "7 天历史"
+      },
+      "pro": {
+        "name": "Pro",
+        "desc": "为挑剔的顾问与创作者。",
+        "cta": "升级到 Pro",
+        "feature0": "无限笔记",
+        "feature1": "BYOK (OpenAI/Anthropic)",
+        "feature2": "200 次语义搜索",
+        "feature3": "智能体（每月 12 次）",
+        "feature4": "30 天历史",
+        "feature5": "邮件支持"
+      },
+      "business": {
+        "name": "Business",
+        "desc": "面向团队与产品经理。",
+        "cta": "选择 Business",
+        "feature0": "含 10 位协作者",
+        "feature1": "BYOK（13 家提供商）",
+        "feature2": "1000 次语义搜索",
+        "feature3": "智能体（每月 60 次）",
+        "feature4": "无限头脑风暴",
+        "feature5": "API 访问"
+      },
+      "enterprise": {
+        "name": "Enterprise",
+        "desc": "安全的组织记忆。",
+        "cta": "联系销售",
+        "feature0": "Business 全部功能",
+        "feature1": "无限智能体",
+        "feature2": "SSO / SAML",
+        "feature3": "审计日志与 SLA",
+        "feature4": "专属支持",
+        "feature5": "现场入门指导"
+      }
+    },
+    "byok": {
+      "label": "开放云技术",
+      "title": "BYOK 策略",
+      "desc": "已有 OpenAI、Anthropic 或 Google 的 API 密钥？直接接入 Momento。无强制额度限制，只按所选提供商的实际消耗付费。",
+      "noLockin": "无锁定",
+      "noLockinDesc": "一键切换提供商。",
+      "cost": "优化成本",
+      "costDesc": "按 API 直连价格付费。",
+      "configLabel": "多提供商配置"
+    },
+    "cta": {
+      "title1": "准备好释放",
+      "title2": "你的全部潜能了吗？",
+      "desc": "加入数千名研究者、设计师与思考者，用 Momento 构建未来。",
+      "button": "启动 Momento"
+    },
+    "footer": {
+      "desc": "AI 放大的第二大脑。为创意头脑而设计。",
+      "product": {
+        "title": "产品",
+        "link0": "更新日志",
+        "link1": "文档",
+        "link2": "路线图",
+        "link0Href": "#",
+        "link1Href": "#",
+        "link2Href": "#"
+      },
+      "community": {
+        "title": "社区",
+        "link0": "Discord",
+        "link1": "Twitter / X",
+        "link2": "LinkedIn",
+        "link0Href": "#",
+        "link1Href": "#",
+        "link2Href": "#"
+      },
+      "legal": {
+        "title": "法律",
+        "link0": "隐私政策",
+        "link1": "服务条款",
+        "link2": "Cookie 政策",
+        "link0Href": "#",
+        "link1Href": "#",
+        "link2Href": "#"
+      }
+    }
   }
-}
+}