revert(budget): drop grace-turn side-effect lockout (#37)

agent/agent_init.py

@@ -1084,9 +1084,6 @@ def init_agent(
     # models to "give up" prematurely on complex tasks (#7915).
     agent._budget_exhausted_injected = False
     agent._budget_grace_call = False
-    # True only during the one post-budget grace turn; read by the tool
-    # dispatchers to refuse side-effecting tools then (Guard D-core).
-    agent._in_budget_grace = False
 
     # Optional wall-clock run budget (seconds per run_conversation turn).
     # Explicit constructor arg wins; else resolved from config.yaml

agent/conversation_loop.py

@@ -2652,20 +2652,8 @@ def run_conversation(
         # Grace call: the budget is exhausted but we gave the model one
         # more chance.  Consume the grace flag so the loop exits after
         # this iteration regardless of outcome.
-        #
-        # ``_in_budget_grace`` is recomputed every iteration (default False) and
-        # set True ONLY for the grace turn. The tool dispatchers read it to
-        # refuse side-effecting tools during the grace turn (deny-by-default,
-        # read-only allowlist) — see ``agent/budget_grace_gate.py`` (Guard
-        # D-core). Refusing a call must NOT re-arm ``_budget_grace_call``: the
-        # flag is already cleared here, so the loop exits after this iteration
-        # whether the model's tool calls execute or are refused. A
-        # deny-that-loops would itself be a runaway, so the gate only blocks
-        # execution; it never extends the loop.
-        agent._in_budget_grace = False
         if agent._budget_grace_call:
             agent._budget_grace_call = False
-            agent._in_budget_grace = True
         elif not agent.iteration_budget.consume():
             _turn_exit_reason = "budget_exhausted"
             if not agent.quiet_mode:

agent/fork_ext/tool_gate.py

@@ -5,8 +5,6 @@
 import json
 from typing import Any
 
-from agent.budget_grace_gate import grace_block_message, is_readonly_grace_tool
-
 
 def tool_search_scoped_names(agent) -> frozenset:
     try:
@@ -80,11 +78,6 @@ def resolve_tool_search_unwrap(agent, function_name: str, function_args: dict[st
 
 
 def pre_tool_block_from_builtin_gate(agent, function_name: str, tool_scope_block: str | None) -> dict[str, str] | None:
-    if getattr(agent, "_in_budget_grace", False) and not is_readonly_grace_tool(function_name):
-        return {
-            "message": grace_block_message(function_name),
-            "error_type": "budget_grace_block",
-        }
     if tool_scope_block is not None:
         return {
             "message": tool_scope_block,

agent/tool_executor.py

@@ -33,9 +33,6 @@
     _detect_tool_failure,
 )
 from agent.tool_guardrails import ToolGuardrailDecision
-from agent.budget_grace_gate import (
-    grace_block_result,
-)
 from agent.fork_ext.tool_gate import (
     pre_tool_block_from_builtin_gate,
     resolve_tool_search_unwrap,
@@ -783,13 +780,8 @@ def _advance_start_order(callback=None) -> None:
             begin_execution(callback)
 
         # ── Block ladder ────────────────────────────────────────────────
-        # parity NOTE (upstream->fork merge 2026-08-08): the fork-only
-        # budget-grace gate (Guard D-core) used to live in each dispatcher.
-        # Upstream moved plugin/scope/guardrail blocking here, so the gate is
-        # re-grafted at the head of THIS ladder — the single choke point both
-        # dispatchers funnel through — rather than duplicated per path. It
-        # runs FIRST so an exhausted-budget turn is refused before any plugin
-        # hook or guardrail bookkeeping observes the call.
+        # Fork tool-search scope block first (agent/fork_ext/tool_gate.py),
+        # then plugin pre_tool_call hooks, then guardrails.
         block_message = pre_tool_block_from_builtin_gate(
             agent, function_name, scope_block
         )
@@ -841,18 +833,9 @@ def _resolve_pre_tool_block():
             _advance_start_order()
             state["blocked"] = True
             if block_message is not None:
-                # parity NOTE (upstream->fork merge 2026-08-08): the fork's
-                # budget-grace refusal must carry the budget_grace_block
-                # metadata key (asserted by test_block_message_and_result_shape
-                # and test_grace_block_result_metadata_key_present_in_real_dispatch),
-                # so it uses the shared grace_block_result() rather than the
-                # generic {"error": ...} envelope every other block emits.
-                if block_error_type == "budget_grace_block":
-                    result = grace_block_result(function_name)
-                else:
-                    result = json.dumps(
-                        {"error": block_message}, ensure_ascii=False
-                    )
+                result = json.dumps(
+                    {"error": block_message}, ensure_ascii=False
+                )
                 error_type = block_error_type
                 error_message = block_message
             else: