feat: add book detail, notes detail, recommendation page and MySQL schema

新增功能：
- 书籍详情弹窗：点击书架书籍展示详细信息（书名、作者、出版社、ISBN、字数、评分、简介、阅读进度），数据实时从微信读书 API 获取并入库
- 笔记详情弹窗：点击有笔记的书展示划线和想法/点评，按章节分组展示，数据实时获取并入库
- 推荐页面：个性化推荐（为你推荐）+ 关键词搜索书籍，数据从微信读书 API 获取并入库
- 修复 Flask 中文 URL 参数编码问题

后端新增 API：
- GET /api/book/detail?book_id=xxx — 书籍详情
- GET /api/book/notes?book_id=xxx — 笔记详情（划线+想法）
- GET /api/recommend?maxIdx=0 — 个性化推荐
- GET /api/search?keyword=xxx — 搜索书籍

数据库新增表：
- book_details, book_progress, book_highlights, book_chapters
- book_reviews, recommended_books, search_results

MySQL 版本建表语句 schema_mysql.sql：
- 18 张表的完整 DDL，含索引、字符集 utf8mb4、字段注释
- 适用于后续从 SQLite 迁移至 MySQL

static/js/app.js

@@ -24,6 +24,7 @@ document.addEventListener("DOMContentLoaded", () => {
     loadTopBooks();
     loadShelf(1);
     loadNotebooks();
+    loadRecommend(0);
     initNavScroll();
 });
 
@@ -525,7 +526,7 @@ async function loadNotebooks() {
             .map((nb) => {
                 const progress = nb.reading_progress || 0;
                 return `
-                <div class="notebook-card">
+                <div class="notebook-card" onclick="openNotes('${nb.book_id}', '${nb.title.replace(/'/g, "\\'")}', '${(nb.author || '').replace(/'/g, "\\'")}', '${nb.cover}')" style="cursor:pointer">
                     <img class="notebook-cover" src="${nb.cover}" alt="${nb.title}"
                          onerror="this.src='data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 width=%2260%22 height=%2280%22%3E%3Crect fill=%22%23e8e0d4%22 width=%2260%22 height=%2280%22/%3E%3C/svg%3E'">
                     <div class="notebook-info">
@@ -548,9 +549,252 @@ async function loadNotebooks() {
     }
 }
 
-// ===== 打开书籍 =====
+// ===== 打开书籍详情弹窗 =====
 function openBook(bookId) {
-    if (bookId) {
-        window.open(`weread://reading?bId=${bookId}`, "_blank");
+    if (!bookId) return;
+    showModal("bookDetailModal");
+    const body = document.getElementById("bookDetailBody");
+    body.innerHTML = `<div class="loading"><div class="loading-spinner"></div></div>`;
+
+    fetchAPI(`/api/book/detail?book_id=${bookId}`)
+        .then((data) => {
+            const p = data.progress || {};
+            const progress = p.progress || 0;
+            const rating = data.new_rating > 0 ? (data.new_rating / 10).toFixed(1) : null;
+            const tags = [];
+            if (data.category) tags.push(data.category);
+            if (rating) tags.push(`${rating}分`);
+            if (data.new_rating_count) tags.push(`${data.new_rating_count}人评分`);
+
+            body.innerHTML = `
+                <div class="detail-header">
+                    <img class="detail-cover" src="${data.cover || ''}" alt="${data.title}"
+                         onerror="this.src='data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 width=%22120%22 height=%22160%22%3E%3Crect fill=%22%23e8e0d4%22 width=%22120%22 height=%22160%22/%3E%3C/svg%3E'">
+                    <div class="detail-meta">
+                        <div class="detail-title">${data.title}</div>
+                        <div class="detail-author">${data.author || ''}${data.translator ? ' / 译: ' + data.translator : ''}</div>
+                        <div class="detail-tags">${tags.map(t => `<span class="detail-tag">${t}</span>`).join('')}</div>
+                        ${progress.is_start_reading ? `
+                        <div class="detail-progress-info">
+                            <div style="font-size:13px;color:var(--text-secondary)">
+                                阅读进度: <strong>${progress.progress}%</strong>
+                                ${progress.record_reading_time_str ? ' · 累计 ' + progress.record_reading_time_str : ''}
+                                ${progress.finish_time ? ' · 读完于 ' + progress.finish_time : ''}
+                            </div>
+                            <div class="detail-progress-bar">
+                                <div class="detail-progress-fill" style="width:${progress}%"></div>
+                            </div>
+                        </div>` : '<div style="font-size:13px;color:var(--text-light);margin-top:8px">尚未开始阅读</div>'}
+                    </div>
+                </div>
+                ${data.intro ? `<div class="detail-intro">${data.intro}</div>` : ''}
+                <div class="detail-info-grid">
+                    ${data.publisher ? `<div class="detail-info-item"><strong>出版社:</strong> ${data.publisher}</div>` : ''}
+                    ${data.publish_time ? `<div class="detail-info-item"><strong>出版时间:</strong> ${data.publish_time}</div>` : ''}
+                    ${data.isbn ? `<div class="detail-info-item"><strong>ISBN:</strong> ${data.isbn}</div>` : ''}
+                    ${data.word_count ? `<div class="detail-info-item"><strong>字数:</strong> ${(data.word_count / 10000).toFixed(1)}万字</div>` : ''}
+                </div>
+                <div class="detail-actions">
+                    <button class="btn-primary" onclick="window.open('weread://reading?bId=${bookId}','_blank')">在微信读书中打开</button>
+                </div>
+            `;
+        })
+        .catch((e) => {
+            body.innerHTML = `<div class="empty-state">加载失败: ${e.message}</div>`;
+        });
+}
+
+// ===== 打开笔记详情弹窗 =====
+function openNotes(bookId, title, author, cover) {
+    if (!bookId) return;
+    showModal("notesDetailModal");
+    const body = document.getElementById("notesDetailBody");
+    body.innerHTML = `
+        <div class="notes-header">
+            <img class="notes-cover" src="${cover || ''}" alt="${title}"
+                 onerror="this.src='data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 width=%2260%22 height=%2280%22%3E%3Crect fill=%22%23e8e0d4%22 width=%2260%22 height=%2280%22/%3E%3C/svg%3E'">
+            <div>
+                <div class="notes-title">${title}</div>
+                <div class="notes-author">${author || ''}</div>
+            </div>
+        </div>
+        <div class="loading"><div class="loading-spinner"></div></div>
+    `;
+
+    fetchAPI(`/api/book/notes?book_id=${bookId}`)
+        .then((data) => {
+            let html = `
+                <div class="notes-header">
+                    <img class="notes-cover" src="${cover || ''}" alt="${title}"
+                         onerror="this.src='data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 width=%2260%22 height=%2280%22%3E%3Crect fill=%22%23e8e0d4%22 width=%2260%22 height=%2280%22/%3E%3C/svg%3E'">
+                    <div>
+                        <div class="notes-title">${title}</div>
+                        <div class="notes-author">${author || ''}</div>
+                        <div class="notes-counts">
+                            <span>划线 <strong>${data.highlight_count}</strong></span>
+                            <span>想法/点评 <strong>${data.review_count}</strong></span>
+                        </div>
+                    </div>
+                </div>
+            `;
+
+            // 划线区
+            if (data.highlight_count > 0) {
+                html += `<div class="notes-section-title">📌 划线 (${data.highlight_count})</div>`;
+                const grouped = data.grouped_highlights;
+                for (const [chTitle, items] of Object.entries(grouped)) {
+                    html += `<div class="chapter-group">`;
+                    html += `<div class="chapter-title">${chTitle}</div>`;
+                    items.forEach((h) => {
+                        html += `
+                            <div class="highlight-item">
+                                ${escapeHtml(h.mark_text)}
+                                <div class="highlight-date">${h.create_time || ''}</div>
+                            </div>
+                        `;
+                    });
+                    html += `</div>`;
+                }
+            }
+
+            // 想法/点评区
+            if (data.review_count > 0) {
+                html += `<div class="notes-section-title">💭 想法/点评 (${data.review_count})</div>`;
+                data.reviews.forEach((r) => {
+                    const stars = r.star > 0 ? `<span class="review-star">${"★".repeat(r.star)}${"☆".repeat(5 - r.star)}</span>` : "";
+                    html += `
+                        <div class="review-item">
+                            ${escapeHtml(r.content)}
+                            <div class="review-meta">
+                                ${stars}
+                                ${r.chapter_name ? ' · ' + r.chapter_name : ''}
+                                ${r.is_finish ? ' · 书评' : ''}
+                                · ${r.create_time || ''}
+                            </div>
+                        </div>
+                    `;
+                });
+            }
+
+            if (data.highlight_count === 0 && data.review_count === 0) {
+                html += `<div class="empty-state">暂无笔记数据</div>`;
+            }
+
+            body.innerHTML = html;
+        })
+        .catch((e) => {
+            body.innerHTML = `<div class="empty-state">加载失败: ${e.message}</div>`;
+        });
+}
+
+// ===== 弹窗控制 =====
+function showModal(id) {
+    document.getElementById(id).classList.add("active");
+    document.body.style.overflow = "hidden";
+}
+
+function closeModal(id) {
+    document.getElementById(id).classList.remove("active");
+    document.body.style.overflow = "";
+}
+
+// ESC 关闭弹窗
+document.addEventListener("keydown", (e) => {
+    if (e.key === "Escape") {
+        closeModal("bookDetailModal");
+        closeModal("notesDetailModal");
+    }
+});
+
+// ===== HTML 转义 =====
+function escapeHtml(text) {
+    if (!text) return "";
+    const div = document.createElement("div");
+    div.textContent = text;
+    return div.innerHTML;
+}
+
+// ===== 推荐发现 =====
+let recommendMaxIdx = 0;
+
+function switchDiscoverTab(tab) {
+    const recPanel = document.getElementById("recommendPanel");
+    const searchPanel = document.getElementById("searchPanel");
+    const tabRec = document.getElementById("tabRecommend");
+    const tabSearch = document.getElementById("tabSearch");
+
+    if (tab === "recommend") {
+        recPanel.style.display = "";
+        searchPanel.style.display = "none";
+        tabRec.classList.add("active");
+        tabSearch.classList.remove("active");
+    } else {
+        recPanel.style.display = "none";
+        searchPanel.style.display = "";
+        tabRec.classList.remove("active");
+        tabSearch.classList.add("active");
     }
 }
+
+async function loadRecommend(maxIdx) {
+    const grid = document.getElementById("recommendGrid");
+    grid.innerHTML = `<div class="loading"><div class="loading-spinner"></div></div>`;
+
+    try {
+        const data = await fetchAPI(`/api/recommend?maxIdx=${maxIdx}`);
+        recommendMaxIdx = data.last_search_idx || 0;
+        renderDiscoverGrid(grid, data.books, true);
+    } catch (e) {
+        grid.innerHTML = `<div class="empty-state">加载推荐失败: ${e.message}</div>`;
+    }
+}
+
+async function loadMoreRecommend() {
+    loadRecommend(recommendMaxIdx);
+}
+
+async function doSearch() {
+    const keyword = document.getElementById("searchInput").value.trim();
+    if (!keyword) return;
+
+    const grid = document.getElementById("searchGrid");
+    grid.innerHTML = `<div class="loading"><div class="loading-spinner"></div></div>`;
+
+    try {
+        const data = await fetchAPI(`/api/search?keyword=${encodeURIComponent(keyword)}`);
+        if (data.books.length === 0) {
+            grid.innerHTML = `<div class="empty-state">未找到相关书籍</div>`;
+            return;
+        }
+        renderDiscoverGrid(grid, data.books, false);
+    } catch (e) {
+        grid.innerHTML = `<div class="empty-state">搜索失败: ${e.message}</div>`;
+    }
+}
+
+function renderDiscoverGrid(grid, books, showReason) {
+    grid.innerHTML = books
+        .map((book) => {
+            const rating = book.new_rating > 0 ? (book.new_rating / 10).toFixed(1) : null;
+            const ratingLabel = book.rating_title ? `<span class="discover-rating-label">${book.rating_title}</span>` : "";
+            const ratingHtml = rating ? `<span class="discover-rating">${rating}</span>` : "";
+            const readingHtml = book.reading_count ? `<span class="discover-reading-count">${book.reading_count}人在读</span>` : "";
+            const reasonHtml = (showReason && book.reason) ? `<div class="discover-reason">${book.reason}</div>` : "";
+            const categoryHtml = book.category ? `<div class="discover-category">${book.category}</div>` : "";
+
+            return `
+                <div class="discover-card" onclick="openBook('${book.book_id}')">
+                    <img class="discover-cover" src="${book.cover || ''}" alt="${book.title}"
+                         onerror="this.src='data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 width=%22200%22 height=%22180%22%3E%3Crect fill=%22%23e8e0d4%22 width=%22200%22 height=%22180%22/%3E%3Ctext x=%22100%22 y=%2290%22 text-anchor=%22middle%22 fill=%22%239b8e80%22 font-size=%2214%22%3E无封面%3C/text%3E%3C/svg%3E'">
+                    <div class="discover-info">
+                        <div class="discover-title">${book.title}</div>
+                        <div class="discover-author">${book.author || ''}</div>
+                        <div class="discover-meta">${ratingHtml}${ratingLabel}${readingHtml}</div>
+                        ${categoryHtml}
+                        ${reasonHtml}
+                    </div>
+                </div>
+            `;
+        })
+        .join("");
+}