feat: adapt review budget to diff size

tests/pilot/review_tests/budget_test.py

@@ -18,6 +18,19 @@ def test_budget_reads_config_over_environment(monkeypatch):
     assert budget.max_steps == 7
 
 
+def test_budget_scales_for_broad_diff():
+    diff = "".join("+changed\n" for _ in range(850))
+    budget = Budget.for_review({}, diff)
+    assert budget.max_steps == 60
+    assert budget.max_total_tokens == 800_000
+
+
+def test_explicit_budget_wins_over_diff_profile():
+    diff = "".join("+changed\n" for _ in range(2_100))
+    budget = Budget.for_review({"budget": {"max_steps": 9}}, diff)
+    assert budget.max_steps == 9
+
+
 def test_budget_state_stops_at_token_limit():
     state = BudgetState(Budget(max_steps=20, max_total_tokens=100))
     assert state.record({"steps": 1, "total": 60, "output": 10}) == ""