feat(export): 新增 export:mobile.heading，导出移动端离线目录 SQLite

替代移动端仓库里 5.5MB 的 tipitaka_heading.json（全量载入内存）。

- heading 表：book/paragraph/level/toc/chapter_len/chapter_strlen/parent/uid，
  口径与原 JSON 一致（level <= 7，共 37411 行）
- 新增 tags 字段：由 pali_texts.uid 经 tag_maps(table_name=pali_texts)/tags
  取标签名，逗号分隔
- 新增 related_paragraph 表：cs_para + book_name + book_id，仅保留源段落本身
  是章节的关联行（51313 行），用于由根本章节定位义注/复注章节起始位置
- --copy-to 可直接把产物复制进移动端仓库

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SvRbrSEBQyJQRMqsDcEm49

api-v13/app/Console/Commands/ExportMobileHeading.php

@@ -0,0 +1,241 @@
+<?php
+
+namespace App\Console\Commands;
+
+use App\Models\PaliText;
+use Illuminate\Console\Command;
+use Illuminate\Support\Facades\DB;
+
+/**
+ * 导出移动端离线目录库（SQLite）。
+ *
+ * 替代 wikipali-mobile 仓库里的 src/data/tipitaka_heading.json（5.5MB，
+ * 全量载入内存）。除原有目录字段外，额外带上：
+ *
+ *  - tags：pali_texts.uid 经 tag_maps / tags 取到的标签名，逗号分隔
+ *  - related_paragraphs：cs_para + book_name，用于由根本章节定位
+ *    对应的义注 / 复注章节起始位置
+ */
+class ExportMobileHeading extends Command
+{
+    protected $signature = 'export:mobile.heading
+        {--out= : 输出文件路径，默认 storage/app/public/export/mobile/tipitaka-heading-<date>.db3}
+        {--max-level=7 : 只导出 level <= 该值的行（与现有 tipitaka_heading.json 口径一致）}
+        {--copy-to= : 导出后额外复制一份到该路径（例如移动端仓库的 assets/db/tipitaka.db3）}';
+
+    protected $description = '导出移动端离线目录 SQLite（含 tags 与义注复注关联段落）';
+
+    public function handle(): int
+    {
+        $maxLevel = (int) $this->option('max-level');
+
+        $out = $this->option('out');
+        if (! $out) {
+            $dir = storage_path('app/public/export/mobile');
+            if (! is_dir($dir)) {
+                mkdir($dir, 0775, true);
+            }
+            $out = $dir.'/tipitaka-heading-'.date('Y-m-d').'.db3';
+        }
+        if (file_exists($out)) {
+            unlink($out);
+        }
+
+        $dbh = new \PDO('sqlite:'.$out, '', '', [\PDO::ATTR_PERSISTENT => true]);
+        $dbh->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
+        $this->createSchema($dbh);
+
+        $headings = $this->exportHeadings($dbh, $maxLevel);
+        $related = $this->exportRelated($dbh, $maxLevel);
+
+        $this->writeMeta($dbh, [
+            'generated_at' => date('c'),
+            'source' => config('app.url', ''),
+            'max_level' => (string) $maxLevel,
+            'heading_rows' => (string) $headings,
+            'related_rows' => (string) $related,
+        ]);
+
+        // 建索引放在插入之后，避免边插边维护索引
+        $this->createIndexes($dbh);
+        $dbh->exec('VACUUM');
+        $dbh = null;
+
+        $this->newLine();
+        $this->info(sprintf(
+            '导出完成：%s（%s，heading %d 行，related %d 行）',
+            $out,
+            $this->humanSize(filesize($out)),
+            $headings,
+            $related
+        ));
+
+        $copyTo = $this->option('copy-to');
+        if ($copyTo) {
+            $dir = dirname($copyTo);
+            if (! is_dir($dir)) {
+                mkdir($dir, 0775, true);
+            }
+            copy($out, $copyTo);
+            $this->info('已复制到：'.$copyTo);
+        }
+
+        return 0;
+    }
+
+    private function createSchema(\PDO $dbh): void
+    {
+        $dbh->exec('CREATE TABLE heading (
+            book INTEGER NOT NULL,
+            paragraph INTEGER NOT NULL,
+            level INTEGER NOT NULL,
+            toc TEXT,
+            chapter_len INTEGER,
+            chapter_strlen INTEGER,
+            parent INTEGER,
+            uid TEXT,
+            tags TEXT,
+            PRIMARY KEY (book, paragraph)
+        )');
+
+        // 一个根本章节可关联多部义注 / 复注，故独立成表
+        $dbh->exec('CREATE TABLE related_paragraph (
+            book INTEGER NOT NULL,
+            para INTEGER NOT NULL,
+            book_id INTEGER,
+            cs_para INTEGER,
+            book_name TEXT
+        )');
+
+        $dbh->exec('CREATE TABLE meta (key TEXT PRIMARY KEY, value TEXT)');
+    }
+
+    private function createIndexes(\PDO $dbh): void
+    {
+        $dbh->exec('CREATE INDEX idx_heading_book_level ON heading (book, level)');
+        $dbh->exec('CREATE INDEX idx_heading_parent ON heading (book, parent)');
+        $dbh->exec('CREATE INDEX idx_related_src ON related_paragraph (book, para)');
+        $dbh->exec('CREATE INDEX idx_related_dst ON related_paragraph (book_name, cs_para)');
+    }
+
+    private function exportHeadings(\PDO $dbh, int $maxLevel): int
+    {
+        $total = PaliText::where('level', '<=', $maxLevel)->count();
+        $this->line("导出 heading（level <= {$maxLevel}）：{$total} 行");
+        $bar = $this->output->createProgressBar($total);
+
+        // uid -> 标签名列表。tag_maps.table_name 对 pali_texts 使用复数表名。
+        $tagsByUid = $this->loadTags();
+
+        $stmt = $dbh->prepare('INSERT INTO heading
+            (book, paragraph, level, toc, chapter_len, chapter_strlen, parent, uid, tags)
+            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)');
+
+        $dbh->beginTransaction();
+        $n = 0;
+        foreach (
+            PaliText::where('level', '<=', $maxLevel)
+                ->select(['uid', 'book', 'paragraph', 'level', 'toc',
+                    'chapter_len', 'chapter_strlen', 'parent'])
+                ->orderBy('book')
+                ->orderBy('paragraph')
+                ->cursor() as $row
+        ) {
+            $stmt->execute([
+                $row->book,
+                $row->paragraph,
+                $row->level,
+                $row->toc,
+                $row->chapter_len,
+                $row->chapter_strlen,
+                $row->parent,
+                $row->uid,
+                isset($tagsByUid[$row->uid]) ? implode(',', $tagsByUid[$row->uid]) : null,
+            ]);
+            $n++;
+            $bar->advance();
+        }
+        $dbh->commit();
+        $bar->finish();
+        $this->newLine();
+
+        return $n;
+    }
+
+    /** @return array<string, string[]> uid => tag names */
+    private function loadTags(): array
+    {
+        $this->line('载入 tag_maps / tags …');
+        $out = [];
+        DB::table('tag_maps')
+            ->join('tags', 'tags.id', '=', 'tag_maps.tag_id')
+            ->where('tag_maps.table_name', 'pali_texts')
+            ->select(['tag_maps.anchor_id', 'tags.name'])
+            ->orderBy('tag_maps.anchor_id')
+            ->chunk(20000, function ($rows) use (&$out) {
+                foreach ($rows as $r) {
+                    $out[$r->anchor_id][] = $r->name;
+                }
+            });
+        $this->line('  标签锚点：'.count($out));
+
+        return $out;
+    }
+
+    /**
+     * 只导出「源段落本身是被导出的 heading」的关联行 ——
+     * 移动端是按章节查关联，非章节段落的关联行用不到。
+     */
+    private function exportRelated(\PDO $dbh, int $maxLevel): int
+    {
+        $sub = DB::table('pali_texts')
+            ->select(['book', 'paragraph'])
+            ->where('level', '<=', $maxLevel);
+
+        $query = DB::table('related_paragraphs as r')
+            ->joinSub($sub, 'h', function ($join) {
+                $join->on('h.book', '=', 'r.book')->on('h.paragraph', '=', 'r.para');
+            })
+            ->select(['r.book', 'r.para', 'r.book_id', 'r.cs_para', 'r.book_name']);
+
+        $total = $query->count();
+        $this->line("导出 related_paragraph：{$total} 行");
+        $bar = $this->output->createProgressBar($total);
+
+        $stmt = $dbh->prepare('INSERT INTO related_paragraph
+            (book, para, book_id, cs_para, book_name) VALUES (?, ?, ?, ?, ?)');
+
+        $dbh->beginTransaction();
+        $n = 0;
+        foreach ($query->orderBy('r.book')->orderBy('r.para')->cursor() as $row) {
+            $stmt->execute([$row->book, $row->para, $row->book_id, $row->cs_para, $row->book_name]);
+            $n++;
+            $bar->advance();
+        }
+        $dbh->commit();
+        $bar->finish();
+        $this->newLine();
+
+        return $n;
+    }
+
+    private function writeMeta(\PDO $dbh, array $meta): void
+    {
+        $stmt = $dbh->prepare('INSERT INTO meta (key, value) VALUES (?, ?)');
+        foreach ($meta as $k => $v) {
+            $stmt->execute([$k, $v]);
+        }
+    }
+
+    private function humanSize(int $bytes): string
+    {
+        $units = ['B', 'KB', 'MB', 'GB'];
+        $i = 0;
+        while ($bytes >= 1024 && $i < count($units) - 1) {
+            $bytes /= 1024;
+            $i++;
+        }
+
+        return round($bytes, 1).' '.$units[$i];
+    }
+}