fix(review): wire full-scrollback replay to an explicit ?full=1, dedup + bound the capture (PR #148)

- Replace the 'missing ?tail means reload' overload with an explicit ?full=1
  query param: the frontend's first buffer load after a page load (selectSession)
  now requests full=1, tab switches keep ?tail=, and the legacy no-param callers
  (response-viewer fallback, clearTerminal refresh) keep the cheap visible-frame
  path — the COD-47 feature was previously unreachable from a real reload.
- When the full-history capture succeeds, return it ALONE instead of prepending
  the byte buffer + \x1b[H\x1b[2J: the capture is the rendered superset of the
  byte history, and ED2 clears only the viewport so the concat replayed the whole
  conversation twice in xterm scrollback. The history+clear+frame concat stays
  for the visible-frame/tab-switch path.
- Pass an explicit execSync maxBuffer for the full-history capture (configured
  terminalBufferMaxBytes + slack) — the 1MB Node default ENOBUFS-killed exactly
  the multi-MB captures the feature exists for; log ENOBUFS concisely instead of
  dumping the truncated stdout.
- Bound the capture itself via -S -<N> derived from the configured tmux
  history limit (was unbounded -S -), and add -J so lines hard-wrapped at the
  capture-time pane width reflow in the browser xterm.
- Cap the concatenated buffer to terminalBufferMaxBytes EARLY (before the
  regex normalization passes) so multi-MB captures don't stall the event loop
  normalizing bytes that get sliced away.
- Tests: route tests updated for ?full=1 semantics (capture-alone response,
  config-forwarded capture bounds, byte-history fallback, no-param requests
  stay on the visible-frame path); source-scan tests cover the bounded -J -S -<N>
  flags and explicit maxBuffer.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/mux-interface.ts

@@ -98,6 +98,20 @@ export interface RespawnPaneOptions {
   historyLimit?: number;
 }
 
+/** Options for pane buffer capture (COD-47 full-history mode). */
+export interface PaneCaptureOptions {
+  /** Capture the entire tmux scrollback instead of just the visible frame. */
+  fullHistory?: boolean;
+  /** Bound the full-history capture to this many scrollback lines (`-S -<N>`). */
+  historyLimitLines?: number;
+  /**
+   * Byte cap the consumer will keep from the capture. Sizes the child-process
+   * stdout buffer (with slack) so multi-MB scrollback dumps aren't killed by
+   * the 1MB execSync default (ENOBUFS).
+   */
+  maxCaptureBytes?: number;
+}
+
 /**
  * Terminal multiplexer interface.
  *
@@ -227,14 +241,14 @@ export interface TerminalMultiplexer extends EventEmitter {
 
   /**
    * Capture a pane's current tmux buffer with ANSI escape codes preserved.
-   * Pass `{ fullHistory: true }` to capture the entire scrollback (`-S -`)
-   * as linear text instead of just the visible single-screen frame (COD-47).
+   * Pass `{ fullHistory: true }` to capture the entire scrollback as linear
+   * text instead of just the visible single-screen frame (COD-47).
    */
-  capturePaneBuffer?(muxName: string, paneTarget?: string, opts?: { fullHistory?: boolean }): string | null;
+  capturePaneBuffer?(muxName: string, paneTarget?: string, opts?: PaneCaptureOptions): string | null;
 
   /**
    * Capture the active pane's current tmux buffer with ANSI escape codes preserved.
    * Pass `{ fullHistory: true }` to capture the entire scrollback (COD-47).
    */
-  captureActivePaneBuffer?(muxName: string, opts?: { fullHistory?: boolean }): string | null;
+  captureActivePaneBuffer?(muxName: string, opts?: PaneCaptureOptions): string | null;
 }