fix(shortcuts): Ctrl+W no longer closes a session

Close Session was bound to Ctrl+W by default. Ctrl+W is delete-word in
every shell, readline prompt and agent CLI, so muscle memory killed the
session (its tmux pane and CLI, with no confirm) mid-sentence, and with
the split pane open it was not even the pane being typed in.

Close Session now has no default key: the capture-phase handler lets
Ctrl+W through and xterm sends ^W to whichever pane is focused. The
action stays in the registry and can be bound in App Settings ->
Shortcuts; the shortcut overlay shows it as not bound. The Help modal,
CLAUDE.md, the split and tile-grid specs and three wiki pages stop
advertising Ctrl+W as kill. Owner decision (tile-grid decision 5).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/wiki/Keyboard-Shortcuts.md

@@ -9,13 +9,16 @@ Press `Ctrl+?` in the app for the same list in a floating overlay.
 | Shortcut                        | Action                                                          |
 | ------------------------------- | --------------------------------------------------------------- |
 | `Ctrl+K` (also `Cmd+K`, `Alt+K`)| Find an open session or start a new one.                         |
-| `Ctrl+W`                        | Kill the active session.                                         |
 | `Ctrl+Tab`                      | Next session.                                                    |
 | `Alt+[` / `Alt+]`               | Previous / next tab.                                             |
 | `Alt+1` to `Alt+9`              | Switch to tab N. Physical keys, so macOS Option layouts work.    |
 | `Ctrl+Shift+{` / `Ctrl+Shift+}` | Move the active tab left / right.                                |
 | `Alt+B`                         | Collapse / expand the session sidebar, when that layout is on.    |
 
+`Ctrl+W` is not a Codeman shortcut: it goes to the terminal, where shells and agent CLIs
+use it to delete the previous word. **Close Session** has no key by default; close a session
+from its tab, or bind a key to it in App Settings → Shortcuts.
+
 ## Terminal
 
 | Shortcut                | Action                                                          |

docs/wiki/Quick-Start.md

@@ -131,7 +131,7 @@ the tmux server or rebooting the machine.
 | To do this                | Do that                                                             |
 | ------------------------- | ------------------------------------------------------------------- |
 | Interrupt the current turn | `Ctrl+C` with nothing selected, or the **Stop** button.            |
-| Close one session          | `Ctrl+W`, or the tab's close control.                              |
+| Close one session          | The tab's close control (`Ctrl+W` is delete-word in the terminal). |
 | Stop the server, keep agents | `codeman web --stop`. The tmux sessions stay alive.              |
 | Stop everything            | `tmux -L codeman kill-server`.                                     |
 

docs/wiki/The-Dashboard.md

@@ -64,7 +64,7 @@ reloading while a permission prompt is blocking does not lose the red tab.
 | Jump to tab N                   | `Alt+1` to `Alt+9` (the number on the tab)              |
 | Next / previous                 | `Ctrl+Tab`, `Alt+[`, `Alt+]`                            |
 | Move the active tab             | `Ctrl+Shift+{`, `Ctrl+Shift+}`                          |
-| Close                           | `Ctrl+W`                                                |
+| Close                           | The tab's close control (no key by default)            |
 | Find any session, open or past  | `Ctrl+K` (also `Cmd+K` and `Alt+K`)                     |
 
 Tabs can also be dragged to reorder.