Merge pull request #246 from Ark0N/fix/idle-detection-working-state

fix: sessions reported idle while working, plus a working state you can see

src/mux-interface.ts

@@ -276,4 +276,13 @@ export interface TerminalMultiplexer extends EventEmitter {
    * Pass `{ fullHistory: true }` to capture the entire scrollback (COD-47).
    */
   captureActivePaneBuffer?(muxName: string, opts?: PaneCaptureOptions): string | null;
+
+  /**
+   * Plain text of the visible frame: no styles, no cursor query, no repaint
+   * reconstruction. Deliberately cheaper than `capturePaneBuffer` because idle
+   * detection calls it on a timer: it only needs to read what the CLI is
+   * currently rendering, never to replay it into an xterm. Returns null when the
+   * pane cannot be read.
+   */
+  capturePaneText?(muxName: string, paneTarget?: string): string | null;
 }