fix(github): drop eager PR diff fetch — judges don't read it anyway

python/cube/commands/peer_review.py

@@ -88,9 +88,7 @@ def _archive_decisions(
             # resumed judge will see prompt-level instructions to ignore
             # any prior decision content anyway.
             pass
-    print_info(
-        f"📦 Archived {len(matches)} prior decision file(s) → " f".prompts/decisions/archive/{archive_root.name}/"
-    )
+    print_info(f"📦 Archived {len(matches)} prior decision file(s) → .prompts/decisions/archive/{archive_root.name}/")
 
 
 def _format_thread_context(threads: list) -> str:
@@ -333,7 +331,7 @@ def _ensure_pr_review_worktree(
                 timeout=60,
             )
             if result.returncode != 0:
-                raise RuntimeError(f"PR review worktree sync failed ({' '.join(cmd)}): " f"{result.stderr.strip()}")
+                raise RuntimeError(f"PR review worktree sync failed ({' '.join(cmd)}): {result.stderr.strip()}")
     else:
         worktree.parent.mkdir(parents=True, exist_ok=True)
         add = subprocess.run(
@@ -456,7 +454,7 @@ def _reconcile_panel_results(
                     ),
                     log_path=None,
                     recovery_command=(
-                        f"cube prv {task_id[len('pr-'):]}"
+                        f"cube prv {task_id[len('pr-') :]}"
                         if disk_status == "missing" and task_id.startswith("pr-")
                         else None
                     ),
@@ -500,7 +498,7 @@ def _reconcile_panel_results(
                     attempts=existing.attempts,
                     error_message="Decision file disappeared after panel completion",
                     log_path=existing.log_path,
-                    recovery_command=(f"cube prv {task_id[len('pr-'):]}" if task_id.startswith("pr-") else None),
+                    recovery_command=(f"cube prv {task_id[len('pr-') :]}" if task_id.startswith("pr-") else None),
                     forcing_follow_up_used=False,
                 )
             )
@@ -564,7 +562,10 @@ def _run_pr_review(
     except Exception as e:
         print_warning(f"Could not fetch from origin: {e}")
 
-    if not pr.diff.strip():
+    # Use the cheap boolean check (git diff --quiet, exit-status only)
+    # instead of fetching diff content. Judges go through the worktree
+    # via Read; we don't need the diff string here.
+    if not pr.has_changes():
         print_warning("PR has no diff - nothing to review")
         raise typer.Exit(0)
 
@@ -774,7 +775,7 @@ def _run_pr_review(
     if missing_judges:
         names = ", ".join(j.label for j in missing_judges)
         print_warning(
-            f"Partial panel failure: {len(missing_judges)} expected judge(s) " f"failed to produce a decision: {names}"
+            f"Partial panel failure: {len(missing_judges)} expected judge(s) failed to produce a decision: {names}"
         )
         print_info("Continuing with available judge decisions...")
 
@@ -854,11 +855,15 @@ def _run_pr_review(
 
     # Use AI deduper to intelligently combine/dedupe all feedback AND merge
     # human_calls across lenses asking the same question.
+    # Lazily compute the diff right before dedupe — capped at 8000
+    # lines, fetched via local git (no API cap). The dedupe prompt
+    # already truncates to ~8000 chars, so this is the right place
+    # to enforce a hard ceiling.
     dedupe_result = run_async(
         run_dedupe_agent(
             feedback=all_feedback,
             existing_comments=existing_comments,
-            pr_diff=pr.diff,
+            pr_diff=pr.get_diff(),
             pr_number=pr_number,
             human_calls=raw_human_calls,
         )
@@ -937,7 +942,7 @@ def _run_pr_review(
             + (f" (+{len(gate.reasons) - 3} more)" if len(gate.reasons) > 3 else "")
         )
     elif post_action == "APPROVE":
-        print_success(f"Auto-approve gate passed — posting APPROVE " f"({approvals}/{expected_total} judges APPROVED)")
+        print_success(f"Auto-approve gate passed — posting APPROVE ({approvals}/{expected_total} judges APPROVED)")
     # Append the gate body to the summary so the GitHub review body explains
     # what the gate saw (judges + reasons, or the clean approval message).
     summary = summary + "\n\n" + gate.body
@@ -1165,7 +1170,7 @@ def _run_branch_review(
         names = ", ".join(j.label for j in missing_judges)
         missing_suffix = f" ⚠️ {len(missing_judges)} judge(s) failed to produce a decision: {names}."
         print_warning(
-            f"Partial panel failure: {len(missing_judges)} expected judge(s) " f"failed to produce a decision: {names}"
+            f"Partial panel failure: {len(missing_judges)} expected judge(s) failed to produce a decision: {names}"
         )
         print_info("Continuing with available judge decisions...")
 
@@ -1238,7 +1243,7 @@ def _run_branch_review(
         for inline in dedupe_result.inline_comments:
             comment = inline.comment
             console.print(
-                f"[yellow]{comment.severity.upper():8}[/yellow] " f"{_rich_escape(str(comment.path))}:{comment.line}"
+                f"[yellow]{comment.severity.upper():8}[/yellow] {_rich_escape(str(comment.path))}:{comment.line}"
             )
             console.print(f"[dim]{_rich_escape(', '.join(inline.judges))}[/dim] {_rich_escape(comment.body)}")
             console.print()

python/cube/commands/ui_review.py

@@ -71,7 +71,18 @@ def _fetch_pr_ui_diff(pr_number: int, repo: Optional[str] = None) -> tuple[str,
         raise RuntimeError("gh CLI not installed or not authenticated. Run: gh auth login")
 
     pr = fetch_pr(pr_number, cwd=str(PROJECT_ROOT), repo=repo)
-    ui_diff = _filter_ui_diff(pr.diff)
+    # UI review filters the diff by extension. Fetch with a generous
+    # ceiling so a huge mixed PR (lots of non-UI changes before the
+    # first UI file) doesn't get its UI hunks dropped to the
+    # truncation marker. The filter shrinks the result to UI-only;
+    # we cap AFTER filtering so the budget applies to relevant content.
+    raw_diff = pr.get_diff(max_lines=1_000_000)
+    ui_diff = _filter_ui_diff(raw_diff)
+    # Now apply a sane cap to the filtered result so prompt size is
+    # bounded even when the UI portion is genuinely huge.
+    ui_lines = ui_diff.splitlines()
+    if len(ui_lines) > 20_000:
+        ui_diff = "\n".join(ui_lines[:20_000]) + f"\n[... {len(ui_lines) - 20_000} more UI-diff lines truncated ...]"
 
     if not ui_diff.strip():
         raise RuntimeError(
@@ -458,7 +469,7 @@ def ui_review_command(
     total = len(findings["P0"]) + len(findings["P1"]) + len(findings["P2"])
     if total > 0:
         print_success(
-            f"UI review complete: {len(findings['P0'])} P0, " f"{len(findings['P1'])} P1, {len(findings['P2'])} P2"
+            f"UI review complete: {len(findings['P0'])} P0, {len(findings['P1'])} P1, {len(findings['P2'])} P2"
         )
     else:
         print_warning("No findings collected from judges")