fix: flatten multiline session titles before printing

CHANGELOG.md

@@ -15,6 +15,7 @@
 
 ### Corrected
 
+- `resume` and `sessions` now flatten newlines/tabs in session titles before printing, so a single session whose title spans multiple lines is no longer miscounted as multiple matches.
 - Braced variables next to Chinese punctuation in CLI messages so macOS Bash does not consume part of a UTF-8 character as a variable name and abort. The existing Linux/macOS smoke suite covers these command paths.
 - Distinguished read-only session lookup from authenticated resume; documented shared-home parallel use as author-reported experience rather than guaranteed isolation or a fixed token lifetime.
 - Installation instructions now use a clone, as required by the existing installer.

codex-switch

@@ -247,6 +247,7 @@ rows = cur.execute("""
 """).fetchall()
 print(f"当前 provider：{prov}（* = 与当前 provider 一致；无 * 的会话用 codex resume <id> 可跨 provider 恢复）")
 for t, mp, tid, title, src in rows:
+    title = (title or '').replace('\n', ' ').replace('\r', ' ').replace('\t', ' ').strip()
     mark = "*" if mp == prov else " "
     print(f"{mark} {t}  {mp:<8} {src:<4} {tid}  {title[:48]}")
 con.close()
@@ -283,7 +284,11 @@ else:
         ORDER BY updated_at DESC
     """, (f"%{kw}%",)).fetchall()
 for r in rows:
-    print("\t".join(r))
+    rid, title, provider, t = r
+    title = (title or '').replace('\n', ' ').replace('\r', ' ').replace('\t', ' ').strip()
+    if len(title) > 60:
+        title = title[:57] + '...'
+    print("\t".join((rid, title, provider, t)))
 con.close()
 PY
 )"

tests/test_smoke.py

@@ -190,6 +190,24 @@ def test_resume_by_session_id(self):
             "-c", 'model_provider="new-provider"', "-c", 'model="new-model"',
         ])
 
+    def test_resume_multiline_title_counts_once(self):
+        self.seed(provider="new-provider", model="new-model")
+        with closing(sqlite3.connect(self.home / "state_5.sqlite")) as db:
+            db.execute(
+                "CREATE TABLE threads "
+                "(id TEXT, title TEXT, model_provider TEXT, updated_at INTEGER, source TEXT)"
+            )
+            db.executemany("INSERT INTO threads VALUES (?, ?, ?, ?, ?)", [
+                ("fixture-multi", "install codex\nstep two\nstep three", "openai", 1700000000, "cli"),
+            ])
+            db.commit()
+        # 标题含换行时，仍应作为「一条」会话命中，而不是被数成多行
+        self.run_cli("resume", "install codex")
+        self.assertEqual(json.loads(self.calls.read_text()), [
+            "resume", "fixture-multi",
+            "-c", 'model_provider="new-provider"', "-c", 'model="new-model"',
+        ])
+
     def test_installer_from_another_directory_and_destination_with_spaces(self):
         destination = self.base / "custom bin"
         result = subprocess.run(