Rework TUI: single-threaded curses, scrollback buffer, server menu

- All curses drawing on the main thread; stdin polled together with the
  ZMQ sockets, Ctrl-C only sets a flag
- Output kept in a 2000-line buffer and redrawn from it, so resizes keep
  the history; PgUp/PgDn and mouse wheel scroll it
- Messages without trailing newline continue the current line (status
  table columns arrive as separate messages)
- Too-small terminal shows a warning instead of exiting
- Start without arguments shows a server selection menu
- Colors on the terminal default background; version 0.9.0

README.md

@@ -34,11 +34,22 @@ duel = 10.13.12.93:28961
 ## Usage
 
 ```bash
+qlpycon                                            # pick a server from a menu
 qlpycon ffa                                        # connect by name
 qlpycon --host tcp://10.13.12.93:28960 --password secret   # connect directly
 qlpycon --list                                     # list configured servers
 ```
 
+Without arguments, qlpycon shows the servers from `[servers]` and connects to the one you select (Up/Down or j/k, Enter or the number key; q quits). If no servers are configured it connects to `[connection] host`.
+
+**Keys in the console:**
+- `Enter`: send the command
+- `Tab`: cycle autocomplete suggestions
+- `Up`/`Down`: command history
+- `PgUp`/`PgDn` or mouse wheel: scroll the output back and forth (the last 2000 lines are kept)
+- Hold `Shift` while selecting text with the mouse (the wheel is reported to qlpycon)
+- `Ctrl-C` twice: quit
+
 **Options:**
 - `--host URI` — ZMQ RCON endpoint
 - `--password PASS` — RCON password (or set `QLPYCON_PASSWORD` env var)
@@ -56,6 +67,7 @@ qlpycon --list                                     # list configured servers
 - Tab autocomplete for cvars and commands with fuzzy matching
 - Argument suggestions for 25+ commands (bot names, maps, gametypes)
 - Command history (↑/↓)
+- Output scrollback (PgUp/PgDn) that survives terminal resizes
 
 ## Architecture