fix: rename bash tool to exec (#748) (thanks @myfunc)

docs/tools/exec.md

@@ -0,0 +1,35 @@
+---
+summary: "Exec tool usage, stdin modes, and TTY support"
+read_when:
+  - Using or modifying the exec tool
+  - Debugging stdin or TTY behavior
+---
+
+# Exec tool
+
+Run shell commands in the workspace. Supports foreground + background execution via `process`.
+If `process` is disallowed, `exec` runs synchronously and ignores `yieldMs`/`background`.
+Background sessions are scoped per agent; `process` only sees sessions from the same agent.
+
+## Parameters
+
+- `command` (required)
+- `yieldMs` (default 10000): auto-background after delay
+- `background` (bool): background immediately
+- `timeout` (seconds, default 1800): kill on expiry
+- `elevated` (bool): run on host if elevated mode is enabled/allowed (only changes behavior when the agent is sandboxed)
+- Need a real TTY? Use the tmux skill.
+Note: `elevated` is ignored when sandboxing is off (exec already runs on the host).
+
+## Examples
+
+Foreground:
+```json
+{"tool":"exec","command":"ls -la"}
+```
+
+Background + poll:
+```json
+{"tool":"exec","command":"npm run build","yieldMs":1000}
+{"tool":"process","action":"poll","sessionId":"<id>"}
+```