feat: server-side attachment thumbnails (480px webp at upload) + session caches - detail grids no longer download full originals

app/server/db.mjs

@@ -125,7 +125,7 @@ function preMigrateColumns(d) {
     }
   };
   for (const t of SYNC_TABLES) addCols(t, SYNC_COLS);
-  addCols('attachment', [['sha256', 'TEXT']]);
+  addCols('attachment', [['sha256', 'TEXT'], ['thumb_rel_path', 'TEXT']]);
 }
 
 export function migrateSync(d) {
@@ -1011,13 +1011,25 @@ function listFootprints(d, query) {
       const abs = path.join(DATA_DIR, rel);
       fs.mkdirSync(path.dirname(abs), { recursive: true });
       fs.writeFileSync(abs, buf);
+      // 服务端缩略图（上传时由客户端 canvas 生成 480px WebP；无则 NULL，读取时回退原图）
+      let thumbRel = null;
+      if (p.thumb_b64) {
+        const tb = Buffer.from(p.thumb_b64, 'base64');
+        if (tb.length) {
+          thumbRel = path.join('attachments', String(p.owner_id), crypto.randomUUID() + '_thumb.webp');
+          const tAbs = path.join(DATA_DIR, thumbRel);
+          fs.mkdirSync(path.dirname(tAbs), { recursive: true });
+          fs.writeFileSync(tAbs, tb);
+          thumbRel = thumbRel.split(path.sep).join('/');
+        }
+      }
       const uuid = uuidv7();
       let item = null;
       withTx(d, () => {
         const h = hlcNext(d);
         const r = d.prepare(
-          "INSERT INTO attachment (owner_type, owner_id, kind, file_name, mime, size, rel_path, sha256, uuid, hlc, origin) VALUES ('footprint',?,?,?,?,?,?,?,?,?,?)"
-        ).run(p.owner_id, null, p.file_name, p.mime ?? null, buf.length, rel.split(path.sep).join('/'), sha, uuid, h, getDeviceId(d));
+          "INSERT INTO attachment (owner_type, owner_id, kind, file_name, mime, size, rel_path, thumb_rel_path, sha256, uuid, hlc, origin) VALUES ('footprint',?,?,?,?,?,?,?,?,?,?,?)"
+        ).run(p.owner_id, null, p.file_name, p.mime ?? null, buf.length, rel.split(path.sep).join('/'), thumbRel, sha, uuid, h, getDeviceId(d));
         item = d.prepare('SELECT * FROM attachment WHERE id=?').get(Number(r.lastInsertRowid));
         touchOplog(d, 'attachment', uuid, 'upsert', h);
       });
@@ -1037,6 +1049,7 @@ function listFootprints(d, query) {
         withTx(d, () => softDelete(d, 'attachment', payload.id));
         const abs = path.join(DATA_DIR, row.rel_path);
         try { fs.unlinkSync(abs); } catch {}
+        if (row.thumb_rel_path) { try { fs.unlinkSync(path.join(DATA_DIR, row.thumb_rel_path)); } catch {} }
       }
       return { ok: true };
     }
@@ -1048,6 +1061,15 @@ function listFootprints(d, query) {
       return { data_b64: data.toString('base64'), mime: row.mime, file_name: row.file_name };
     }
 
+    case 'attachment_thumb': {
+      // 缩略图读取：有服务端缩略图用之（20KB 级 WebP），老附件回退原图
+      const row = d.prepare('SELECT * FROM attachment WHERE id=?').get(payload.id);
+      if (!row) throw new Error('附件不存在');
+      const rel = row.thumb_rel_path || row.rel_path;
+      const data = fs.readFileSync(path.join(DATA_DIR, rel));
+      return { data_b64: data.toString('base64'), mime: row.thumb_rel_path ? 'image/webp' : row.mime, file_name: row.file_name };
+    }
+
     case 'view_list':
       return { items: d.prepare('SELECT * FROM saved_view WHERE deleted_at IS NULL ORDER BY id').all().map(v => ({
         ...v, filter: JSON.parse(v.filter || '{}'), sort: JSON.parse(v.sort || '{}'), is_default: !!v.is_default