diff --git a/server.js b/server.js
index 98d1497b..743ed118 100644
--- a/server.js
+++ b/server.js
@@ -88,7 +88,7 @@ if (!process.env.JWT_SECRET) {
     process.exit(1);
 }
 const JWT_SECRET = process.env.JWT_SECRET;
-const JWT_TTL_SECONDS = 30 * 24 * 60 * 60; // 30 days
+const JWT_TTL_SECONDS = 7 * 24 * 60 * 60; // 7 days
 
 // WebAuthn relying party config (from env)
 const WEBAUTHN_RP_NAME   = process.env.WEBAUTHN_RP_NAME   || 'Posimai';
@@ -760,13 +760,41 @@ function getTogetherJwtUserId(req) {
     return getOptionalJwtUserIdFromHeader(req);
 }
 
+function normalizeTogetherUsername(value) {
+    if (typeof value !== 'string') return null;
+    const trimmed = value.trim();
+    return trimmed ? trimmed : null;
+}
+
+async function resolveTogetherUserCandidates(pool, username, jwtUserId) {
+    const candidates = [];
+    const normalizedUsername = normalizeTogetherUsername(username);
+    if (normalizedUsername) candidates.push(normalizedUsername);
+    if (jwtUserId) candidates.push(jwtUserId);
+    if (jwtUserId) {
+        const userResult = await pool.query(
+            'SELECT user_id, name FROM users WHERE user_id=$1 LIMIT 1',
+            [jwtUserId]
+        );
+        const user = userResult.rows[0];
+        if (user) {
+            const userId = normalizeTogetherUsername(user.user_id);
+            const userName = normalizeTogetherUsername(user.name);
+            if (userId) candidates.push(userId);
+            if (userName) candidates.push(userName);
+        }
+    }
+    return [...new Set(candidates)];
+}
+
 /**
  * Together メンバー確認。JWT なしのときは従来どおり username のみ（完全互換）。
  * JWT ありのときは user_id 一致、または未紐付けメンバーで username が JWT ユーザーの user_id/name と一致する場合は厳格一致。
  * それ以外の未紐付けニックネームは従来クエリで許可し warn ログ（運用互換）。
  */
 async function togetherEnsureMember(pool, res, groupId, username, jwtUserId) {
-    if (!username || typeof username !== 'string') {
+    const usernames = await resolveTogetherUserCandidates(pool, username, jwtUserId);
+    if (usernames.length === 0) {
         res.status(400).json({ error: 'username が不正です' });
         return false;
     }
@@ -783,32 +811,29 @@ async function togetherEnsureMember(pool, res, groupId, username, jwtUserId) {
                    m.user_id = $2
                    OR (
                      (m.user_id IS NULL OR btrim(COALESCE(m.user_id, '')) = '')
-                     AND m.username = $3
-                     AND EXISTS (
-                       SELECT 1 FROM users u
-                       WHERE u.user_id = $2 AND (u.user_id = $3 OR u.name = $3)
-                     )
+                     AND m.username = ANY($3::text[])
                    )
                  )`,
-                [gidNum, jwtUserId, username]
+                [gidNum, jwtUserId, usernames]
             );
             if (strict.rows.length > 0) return true;
 
             const legacy = await pool.query(
-                'SELECT 1 FROM together_members WHERE group_id=$1 AND username=$2',
-                [gidNum, username]
+                'SELECT 1 FROM together_members WHERE group_id=$1 AND username = ANY($2::text[])',
+                [gidNum, usernames]
             );
             if (legacy.rows.length > 0) {
                 // user_id 未紐付け期間の暫定: メンバー行があれば許可（紐付け完了後に削除予定）
-                console.warn('[Together] legacy path used user=%s username=%s group=%s', jwtUserId, username, gidNum);
+                console.warn('[Together] legacy path used user=%s usernames=%j group=%s', jwtUserId, usernames, gidNum);
                 return true;
             }
             res.status(403).json({ error: 'グループのメンバーではありません' });
             return false;
         }
+        const primaryUsername = usernames[0];
         const legacyOnly = await pool.query(
             'SELECT 1 FROM together_members WHERE group_id=$1 AND username=$2',
-            [gidNum, username]
+            [gidNum, primaryUsername]
         );
         if (legacyOnly.rows.length === 0) {
             res.status(403).json({ error: 'グループのメンバーではありません' });
@@ -2388,7 +2413,7 @@ ${excerpt}
             res.send(audioBuffer);
         } catch (e) {
             console.error('[TTS]', e.message);
-            res.status(503).json({ error: 'TTS_UNAVAILABLE', detail: e.message });
+            res.status(503).json({ error: 'TTS_UNAVAILABLE' });
         } finally {
             ttsBusy = false;
         }
@@ -2421,7 +2446,8 @@ ${excerpt}
             const speakers = await r2.json();
             res.json(speakers);
         } catch (e) {
-            res.status(503).json({ error: 'TTS_UNAVAILABLE', detail: e.message });
+            console.error('[TTS/speakers]', e.message);
+            res.status(503).json({ error: 'TTS_UNAVAILABLE' });
         }
     });
 
@@ -2589,6 +2615,15 @@ ${excerpt}
     r.post('/together/groups', async (req, res) => {
         const { name, username } = req.body || {};
         if (!name || !username) return res.status(400).json({ error: 'name と username は必須です' });
+        // JWT が提示されている場合、body の username と一致するか確認（なりすまし防止）
+        const jwtUserId = getTogetherJwtUserId(req);
+        if (jwtUserId) {
+            const requested = normalizeTogetherUsername(username);
+            const jwtCandidates = await resolveTogetherUserCandidates(pool, null, jwtUserId);
+            if (!requested || !jwtCandidates.includes(requested)) {
+                return res.status(403).json({ error: '認証情報とユーザー名が一致しません' });
+            }
+        }
         if (!checkRateLimit('together_create', req.ip || 'unknown', 5, 60 * 60 * 1000)) {
             return res.status(429).json({ error: 'グループ作成の上限に達しました。1時間後に再試行してください' });
         }
@@ -2619,6 +2654,15 @@ ${excerpt}
     r.post('/together/join', async (req, res) => {
         const { invite_code, username } = req.body || {};
         if (!invite_code || !username) return res.status(400).json({ error: 'invite_code と username は必須です' });
+        // JWT が提示されている場合、body の username と一致するか確認（なりすまし防止）
+        const jwtUserId = getTogetherJwtUserId(req);
+        if (jwtUserId) {
+            const requested = normalizeTogetherUsername(username);
+            const jwtCandidates = await resolveTogetherUserCandidates(pool, null, jwtUserId);
+            if (!requested || !jwtCandidates.includes(requested)) {
+                return res.status(403).json({ error: '認証情報とユーザー名が一致しません' });
+            }
+        }
         if (!checkRateLimit('together_join', req.ip || 'unknown', 10, 60 * 60 * 1000)) {
             return res.status(429).json({ error: '参加試行回数が上限に達しました。1時間後に再試行してください' });
         }
@@ -2642,8 +2686,7 @@ ${excerpt}
     // GET /together/groups/:groupId — グループ情報（メンバーのみ）
     r.get('/together/groups/:groupId', async (req, res) => {
         if (!/^[a-zA-Z0-9_-]+$/.test(req.params.groupId)) return res.status(400).json({ error: 'invalid groupId' });
-        const username = req.query.u;
-        if (!username) return res.status(400).json({ error: 'u (username) は必須です' });
+        const username = normalizeTogetherUsername(req.query.u);
         const jwtUserId = getTogetherJwtUserId(req);
         try {
             if (!(await togetherEnsureMember(pool, res, req.params.groupId, username, jwtUserId))) return;
@@ -2657,8 +2700,7 @@ ${excerpt}
 
     // GET /together/members/:groupId — メンバー一覧 ?u=username
     r.get('/together/members/:groupId', async (req, res) => {
-        const username = req.query.u;
-        if (!username) return res.status(400).json({ error: 'u (username) は必須です' });
+        const username = normalizeTogetherUsername(req.query.u);
         const jwtUserId = getTogetherJwtUserId(req);
         try {
             if (!(await togetherEnsureMember(pool, res, req.params.groupId, username, jwtUserId))) return;
@@ -2676,21 +2718,24 @@ ${excerpt}
     // POST /together/share — 記事・テキストをシェア（即返却 + 非同期アーカイブ）
     r.post('/together/share', async (req, res) => {
         const { group_id, shared_by, url = null, title = null, message = '', tags = [] } = req.body || {};
-        if (!group_id || !shared_by) return res.status(400).json({ error: 'group_id と shared_by は必須です' });
+        if (!group_id) return res.status(400).json({ error: 'group_id は必須です' });
         if (url) {
             if (!isSsrfSafe(url)) return res.status(400).json({ error: 'url は http/https のみ有効です' });
         }
         const jwtUserId = getTogetherJwtUserId(req);
         try {
+            const candidates = await resolveTogetherUserCandidates(pool, shared_by, jwtUserId);
+            const actor = candidates[0] || null;
+            if (!actor) return res.status(400).json({ error: 'shared_by が不正です' });
             const grpCheck = await pool.query('SELECT id FROM together_groups WHERE id=$1', [group_id]);
             if (grpCheck.rows.length === 0) return res.status(404).json({ error: 'グループが見つかりません' });
 
-            if (!(await togetherEnsureMember(pool, res, group_id, shared_by, jwtUserId))) return;
+            if (!(await togetherEnsureMember(pool, res, group_id, actor, jwtUserId))) return;
 
             const result = await pool.query(
                 `INSERT INTO together_shares (group_id, shared_by, url, title, message, tags)
                  VALUES ($1, $2, $3, $4, $5, $6) RETURNING *`,
-                [group_id, shared_by, url, title, message, tags]
+                [group_id, actor, url, title, message, tags]
             );
             const share = result.rows[0];
             res.json({ ok: true, share });
@@ -2698,7 +2743,7 @@ ${excerpt}
             // URL がある場合のみ非同期アーカイブ（ユーザーを待たせない）
             // shared_by ごとに 20回/時間 の Gemini 呼び出し制限
             if (url) {
-                if (checkRateLimit('together_archive', shared_by, 20, 60 * 60 * 1000)) {
+                if (checkRateLimit('together_archive', actor, 20, 60 * 60 * 1000)) {
                     archiveShare(share.id, url);
                 } else {
                     pool.query(`UPDATE together_shares SET archive_status='skipped' WHERE id=$1`, [share.id]).catch(() => {});
@@ -2734,8 +2779,7 @@ ${excerpt}
     // GET /together/feed/:groupId — フィード（リアクション付き）
     // ?u=username&limit=N&cursor=<ISO timestamp>
     r.get('/together/feed/:groupId', async (req, res) => {
-        const username = req.query.u;
-        if (!username) return res.status(400).json({ error: 'u (username) は必須です' });
+        const username = normalizeTogetherUsername(req.query.u);
         const jwtUserId = getTogetherJwtUserId(req);
         try {
             if (!(await togetherEnsureMember(pool, res, req.params.groupId, username, jwtUserId))) return;
@@ -2751,6 +2795,9 @@ ${excerpt}
             const result = await pool.query(`
                 SELECT
                     s.*,
+                    s.full_content AS full_text,
+                    COALESCE(s.tags, '{}') AS topics,
+                    (s.full_content IS NOT NULL AND btrim(s.full_content) <> '') AS has_full_text,
                     COALESCE(
                         json_agg(DISTINCT jsonb_build_object('username', r.username, 'type', r.type))
                         FILTER (WHERE r.username IS NOT NULL), '[]'
@@ -2775,14 +2822,26 @@ ${excerpt}
 
     // GET /together/article/:shareId — アーカイブ本文取得 ?u=username
     r.get('/together/article/:shareId', async (req, res) => {
-        const username = req.query.u;
-        if (!username) return res.status(400).json({ error: 'u (username) は必須です' });
+        const username = normalizeTogetherUsername(req.query.u);
         const jwtUserId = getTogetherJwtUserId(req);
         try {
             if (!(await togetherEnsureMemberForShare(pool, res, req.params.shareId, username, jwtUserId))) return;
 
             const result = await pool.query(
-                'SELECT id, title, url, full_content, summary, archive_status, shared_at FROM together_shares WHERE id=$1',
+                `SELECT
+                    id,
+                    title,
+                    url,
+                    full_content,
+                    full_content AS full_text,
+                    summary,
+                    COALESCE(tags, '{}') AS tags,
+                    COALESCE(tags, '{}') AS topics,
+                    (full_content IS NOT NULL AND btrim(full_content) <> '') AS has_full_text,
+                    archive_status,
+                    shared_at
+                 FROM together_shares
+                 WHERE id=$1`,
                 [req.params.shareId]
             );
             if (result.rows.length === 0) return res.status(404).json({ error: '見つかりません' });
@@ -2826,8 +2885,7 @@ ${excerpt}
 
     // GET /together/comments/:shareId — コメント一覧 ?u=username
     r.get('/together/comments/:shareId', async (req, res) => {
-        const username = req.query.u;
-        if (!username) return res.status(400).json({ error: 'u (username) は必須です' });
+        const username = normalizeTogetherUsername(req.query.u);
         const jwtUserId = getTogetherJwtUserId(req);
         try {
             if (!(await togetherEnsureMemberForShare(pool, res, req.params.shareId, username, jwtUserId))) return;
@@ -2866,7 +2924,6 @@ ${excerpt}
     // GET /together/search/:groupId — キーワード / タグ検索 ?u=username
     r.get('/together/search/:groupId', async (req, res) => {
         const { q = '', tag = '', u: username = '' } = req.query;
-        if (!username) return res.status(400).json({ error: 'u (username) は必須です' });
         const jwtUserId = getTogetherJwtUserId(req);
         if (!(await togetherEnsureMember(pool, res, req.params.groupId, username, jwtUserId))) return;
         if (!q && !tag) return res.status(400).json({ error: 'q または tag が必要です' });
@@ -2987,7 +3044,7 @@ ${excerpt}
             });
         });
         req2.on('timeout', () => { req2.destroy(); res.status(500).json({ error: 'Timeout' }); });
-        req2.on('error', (e) => { console.error('[proxy] error:', e.code, e.message); res.status(500).json({ error: 'Proxy error', code: e.code }); });
+        req2.on('error', (e) => { console.error('[proxy] error:', e.code, e.message); res.status(500).json({ error: 'Proxy error' }); });
         req2.end();
     });