Harden tmux session isolation, improve interactive pane capture reliability, and add /kill command

README.md

@@ -148,6 +148,7 @@ uv run ccbot
 | `/history`    | Message history for this topic  |
 | `/screenshot` | Capture terminal screenshot     |
 | `/esc`        | Send Escape to interrupt Claude |
+| `/kill`       | Kill session and unbind topic   |
 
 **Claude Code commands (forwarded via tmux):**
 
@@ -179,7 +180,8 @@ Once a topic is bound to a session, just send text in that topic — it gets for
 
 **Killing a session:**
 
-Close (or delete) the topic in Telegram. The associated tmux window is automatically killed and the binding is removed.
+Use `/kill` in the topic to kill its bound tmux window and unbind the topic.  
+You can also close (or delete) the topic in Telegram — this also auto-kills the associated tmux window and removes the binding.
 
 ### Message History
 

README_CN.md

@@ -144,6 +144,7 @@ uv run ccbot
 | `/history` | 当前话题的消息历史 |
 | `/screenshot` | 截取终端屏幕 |
 | `/esc` | 发送 Escape 键中断 Claude |
+| `/kill` | 终止会话并解绑当前话题 |
 
 **Claude Code 命令（通过 tmux 转发）：**
 
@@ -175,7 +176,8 @@ uv run ccbot
 
 **关闭会话：**
 
-在 Telegram 中关闭（或删除）话题，关联的 tmux 窗口会自动终止，绑定也会被移除。
+在话题里使用 `/kill`，可终止该话题绑定的 tmux 窗口并解绑话题。  
+也可以在 Telegram 中关闭（或删除）话题：关联的 tmux 窗口同样会自动终止，绑定会被移除。
 
 ### 消息历史
 

README_RU.md

@@ -146,6 +146,7 @@ uv run ccbot
 | `/history` | История сообщений для текущего topic |
 | `/screenshot` | Снимок терминала |
 | `/esc` | Отправить Escape для прерывания Claude |
+| `/kill` | Завершить сессию и отвязать topic |
 
 **Команды Claude Code (пробрасываются через tmux):**
 
@@ -177,7 +178,8 @@ uv run ccbot
 
 **Завершение сессии:**
 
-Закройте (или удалите) topic в Telegram. Связанное tmux-окно будет автоматически завершено, привязка удалена.
+Используйте `/kill` в topic, чтобы завершить связанное tmux-окно и отвязать topic.  
+Также можно закрыть (или удалить) topic в Telegram — это тоже автоматически завершит связанное tmux-окно и удалит привязку.
 
 ### История сообщений
 

pyproject.toml

@@ -11,6 +11,7 @@ dependencies = [
     "libtmux>=0.37.0",
     "Pillow>=10.0.0",
     "aiofiles>=24.0.0",
+    "mistletoe>=1.4.0",
     "telegramify-markdown>=0.5.0",
 ]
 

src/ccbot/bot.py

@@ -170,6 +170,11 @@ def _get_thread_id(update: Update) -> int | None:
     return tid
 
 
+def _default_browse_path() -> str:
+    """Default root for directory browser navigation."""
+    return str(Path.home())
+
+
 # --- Command handlers ---
 
 
@@ -243,6 +248,47 @@ async def screenshot_command(
     )
 
 
+async def kill_command(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Kill the bound tmux window for this topic and unbind the thread."""
+    user = update.effective_user
+    if not user or not is_user_allowed(user.id):
+        return
+    if not update.message:
+        return
+
+    thread_id = _get_thread_id(update)
+    if thread_id is None:
+        await safe_reply(update.message, "❌ This command only works in a topic.")
+        return
+
+    wid = session_manager.get_window_for_thread(user.id, thread_id)
+    if not wid:
+        await safe_reply(update.message, "❌ No session bound to this topic.")
+        return
+
+    display = session_manager.get_display_name(wid)
+    w = await tmux_manager.find_window_by_id(wid)
+    if w:
+        killed = await tmux_manager.kill_window(w.window_id)
+        if not killed:
+            await safe_reply(update.message, f"❌ Failed to kill window '{display}'.")
+            return
+    else:
+        logger.info(
+            "Kill requested: window %s already gone (user=%d, thread=%d)",
+            display,
+            user.id,
+            thread_id,
+        )
+
+    session_manager.unbind_thread(user.id, thread_id)
+    await clear_topic_state(user.id, thread_id, context.bot, context.user_data)
+    await safe_reply(
+        update.message,
+        f"✅ Killed window '{display}' and unbound this topic.",
+    )
+
+
 async def unbind_command(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
     """Unbind this topic from its Claude session without killing the window."""
     user = update.effective_user
@@ -837,7 +883,7 @@ async def text_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -> No
             user.id,
             thread_id,
         )
-        start_path = str(Path.cwd())
+        start_path = _default_browse_path()
         msg_text, keyboard, subdirs = build_directory_browser(start_path)
         if context.user_data is not None:
             context.user_data[STATE_KEY] = STATE_BROWSING_DIRECTORY
@@ -1109,7 +1155,7 @@ async def callback_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -
             return
         subdir_name = cached_dirs[idx]
 
-        default_path = str(Path.cwd())
+        default_path = _default_browse_path()
         current_path = (
             context.user_data.get(BROWSE_PATH_KEY, default_path)
             if context.user_data
@@ -1139,7 +1185,7 @@ async def callback_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -
         if pending_tid is not None and _get_thread_id(update) != pending_tid:
             await query.answer("Stale browser (topic mismatch)", show_alert=True)
             return
-        default_path = str(Path.cwd())
+        default_path = _default_browse_path()
         current_path = (
             context.user_data.get(BROWSE_PATH_KEY, default_path)
             if context.user_data
@@ -1172,7 +1218,7 @@ async def callback_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -
         except ValueError:
             await query.answer("Invalid data")
             return
-        default_path = str(Path.cwd())
+        default_path = _default_browse_path()
         current_path = (
             context.user_data.get(BROWSE_PATH_KEY, default_path)
             if context.user_data
@@ -1188,7 +1234,7 @@ async def callback_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -
         await query.answer()
 
     elif data == CB_DIR_CONFIRM:
-        default_path = str(Path.cwd())
+        default_path = _default_browse_path()
         selected_path = (
             context.user_data.get(BROWSE_PATH_KEY, default_path)
             if context.user_data
@@ -1409,7 +1455,7 @@ async def callback_handler(update: Update, context: ContextTypes.DEFAULT_TYPE) -
             return
         # Preserve pending thread info, clear only picker state
         clear_window_picker_state(context.user_data)
-        start_path = str(Path.cwd())
+        start_path = _default_browse_path()
         msg_text, keyboard, subdirs = build_directory_browser(start_path)
         if context.user_data is not None:
             context.user_data[STATE_KEY] = STATE_BROWSING_DIRECTORY
@@ -1715,7 +1761,7 @@ async def post_init(application: Application) -> None:
         BotCommand("history", "Message history for this topic"),
         BotCommand("screenshot", "Terminal screenshot with control keys"),
         BotCommand("esc", "Send Escape to interrupt Claude"),
-        BotCommand("kill", "Kill session and delete topic"),
+        BotCommand("kill", "Kill session window and unbind topic"),
         BotCommand("unbind", "Unbind topic from session (keeps window running)"),
         BotCommand("usage", "Show Claude Code usage remaining"),
     ]
@@ -1789,6 +1835,7 @@ def create_bot() -> Application:
     application.add_handler(CommandHandler("history", history_command))
     application.add_handler(CommandHandler("screenshot", screenshot_command))
     application.add_handler(CommandHandler("esc", esc_command))
+    application.add_handler(CommandHandler("kill", kill_command))
     application.add_handler(CommandHandler("unbind", unbind_command))
     application.add_handler(CommandHandler("usage", usage_command))
     application.add_handler(CallbackQueryHandler(callback_handler))

src/ccbot/handlers/directory_browser.py

@@ -128,7 +128,7 @@ def build_directory_browser(
     """
     path = Path(current_path).expanduser().resolve()
     if not path.exists() or not path.is_dir():
-        path = Path.cwd()
+        path = Path.home()
 
     try:
         subdirs = sorted(

src/ccbot/tmux_manager.py

@@ -15,6 +15,7 @@
 
 import asyncio
 import logging
+import shlex
 from dataclasses import dataclass
 from pathlib import Path
 
@@ -38,6 +39,10 @@ class TmuxWindow:
 class TmuxManager:
     """Manages tmux windows for Claude Code sessions."""
 
+    DEFAULT_WINDOW_WIDTH = 200
+    DEFAULT_WINDOW_HEIGHT = 50
+    DEFAULT_CAPTURE_SCROLLBACK_LINES = 2000
+
     def __init__(self, session_name: str | None = None):
         """Initialize tmux manager.
 
@@ -92,6 +97,24 @@ def _scrub_session_env(session: libtmux.Session) -> None:
             except Exception:
                 pass  # var not set in session env — nothing to remove
 
+    def _build_claude_launch_command(
+        self, path: Path, resume_session_id: str | None = None
+    ) -> str:
+        """Build shell command to launch Claude in a clean project context.
+
+        `uv run ccbot` exports VIRTUAL_ENV and UV_* variables from the bot's
+        own project. Unset them so `uv` calls inside Claude resolve against
+        the selected directory, not the bot workspace.
+        """
+        cmd = config.claude_command
+        if resume_session_id:
+            cmd = f"{cmd} --resume {resume_session_id}"
+        return (
+            f"cd {shlex.quote(str(path))} && "
+            "unset VIRTUAL_ENV UV_PROJECT UV_WORKING_DIRECTORY && "
+            f"{cmd}"
+        )
+
     async def list_windows(self) -> list[TmuxWindow]:
         """List all windows in the session with their working directories.
 
@@ -170,7 +193,7 @@ async def find_window_by_id(self, window_id: str) -> TmuxWindow | None:
         return None
 
     async def capture_pane(self, window_id: str, with_ansi: bool = False) -> str | None:
-        """Capture the visible text content of a window's active pane.
+        """Capture pane text for a window.
 
         Args:
             window_id: The window ID to capture
@@ -179,31 +202,37 @@ async def capture_pane(self, window_id: str, with_ansi: bool = False) -> str | N
         Returns:
             The captured text, or None on failure.
         """
+        # Use tmux capture-pane for both ANSI and plain captures.
+        # For plain text, include recent scrollback to reduce missed content
+        # when pane viewport is smaller than the active output region.
+        args = ["tmux", "capture-pane"]
         if with_ansi:
-            # Use async subprocess to call tmux capture-pane -e for ANSI colors
-            try:
-                proc = await asyncio.create_subprocess_exec(
-                    "tmux",
-                    "capture-pane",
-                    "-e",
-                    "-p",
-                    "-t",
-                    window_id,
-                    stdout=asyncio.subprocess.PIPE,
-                    stderr=asyncio.subprocess.PIPE,
-                )
-                stdout, stderr = await proc.communicate()
-                if proc.returncode == 0:
-                    return stdout.decode("utf-8")
-                logger.error(
-                    f"Failed to capture pane {window_id}: {stderr.decode('utf-8')}"
-                )
-                return None
-            except Exception as e:
-                logger.error(f"Unexpected error capturing pane {window_id}: {e}")
-                return None
+            args.append("-e")
+        else:
+            args.extend(["-S", f"-{self.DEFAULT_CAPTURE_SCROLLBACK_LINES}"])
+        args.extend(["-p", "-t", window_id])
+
+        try:
+            proc = await asyncio.create_subprocess_exec(
+                *args,
+                stdout=asyncio.subprocess.PIPE,
+                stderr=asyncio.subprocess.PIPE,
+            )
+            stdout, stderr = await proc.communicate()
+            if proc.returncode == 0:
+                return stdout.decode("utf-8")
+            logger.error(
+                "Failed to capture pane %s: %s",
+                window_id,
+                stderr.decode("utf-8"),
+            )
+        except Exception as e:
+            logger.error(f"Unexpected error capturing pane {window_id}: {e}")
+
+        # Fallback for plain-text path.
+        if with_ansi:
+            return None
 
-        # Original implementation for plain text - wrap in thread
         def _sync_capture() -> str | None:
             session = self.get_session()
             if not session:
@@ -410,6 +439,29 @@ def _create_and_start() -> tuple[bool, str, str, str]:
                 )
 
                 wid = window.window_id or ""
+                target = wid or f"{self.session_name}:{final_window_name}"
+
+                # Keep this window at a stable manual size to reduce TUI wrapping
+                # variance and improve parser reliability.
+                try:
+                    self.server.cmd(
+                        "set-option",
+                        "-t",
+                        self.session_name,
+                        "window-size",
+                        "manual",
+                    )
+                    self.server.cmd(
+                        "resize-window",
+                        "-t",
+                        target,
+                        "-x",
+                        str(self.DEFAULT_WINDOW_WIDTH),
+                        "-y",
+                        str(self.DEFAULT_WINDOW_HEIGHT),
+                    )
+                except Exception as e:
+                    logger.warning("Failed to apply window size for %s: %s", target, e)
 
                 # Prevent Claude Code from overriding window name
                 window.set_window_option("allow-rename", "off")
@@ -418,16 +470,18 @@ def _create_and_start() -> tuple[bool, str, str, str]:
                 if start_claude:
                     pane = window.active_pane
                     if pane:
-                        cmd = config.claude_command
-                        if resume_session_id:
-                            cmd = f"{cmd} --resume {resume_session_id}"
-                        pane.send_keys(cmd, enter=True)
+                        launch_cmd = self._build_claude_launch_command(
+                            path, resume_session_id
+                        )
+                        pane.send_keys(launch_cmd, enter=True)
 
                 logger.info(
-                    "Created window '%s' (id=%s) at %s",
+                    "Created window '%s' (id=%s) at %s (%sx%s)",
                     final_window_name,
                     wid,
                     path,
+                    self.DEFAULT_WINDOW_WIDTH,
+                    self.DEFAULT_WINDOW_HEIGHT,
                 )
                 return (
                     True,