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/web/public/app.js

@@ -324,6 +324,7 @@ class CodemanApp {
     this._initGeneration = 0;     // dedup concurrent handleInit calls
     this._initFallbackTimer = null; // fallback timer if SSE init doesn't arrive
     this._selectGeneration = 0;   // cancel stale selectSession loads
+    this._initialFullBufferLoad = true; // first buffer load after a page load fetches full tmux scrollback (COD-47)
     this.terminalLoadStates = new Map(); // Map<sessionId, { generation, phase }>
     this.respawnStatus = {};
     this.respawnTimers = {}; // Track timed respawn timers
@@ -3705,7 +3706,16 @@ class CodemanApp {
 
       this._setTerminalLoadState(sessionId, selectGen, 'fetching');
       _crashDiag.log('FETCH_START');
-      const res = await fetch(`/api/sessions/${sessionId}/terminal?tail=${TERMINAL_TAIL_SIZE}`);
+      // The FIRST buffer load after a page load requests the full tmux scrollback
+      // (?full=1, COD-47) so history that scrolled off the server's byte buffer
+      // comes back after a reload. Tab switches keep the fast ?tail= frame path.
+      const useFullHistory = this._initialFullBufferLoad === true;
+      this._initialFullBufferLoad = false;
+      const res = await fetch(
+        useFullHistory
+          ? `/api/sessions/${sessionId}/terminal?full=1`
+          : `/api/sessions/${sessionId}/terminal?tail=${TERMINAL_TAIL_SIZE}`
+      );
       if (this._isStaleSelect(selectGen)) {
         this._clearTerminalLoadState(sessionId, selectGen);
         return;