Allow idempotent reconfirmation of resolved investigation questions

docs/investigation-loop-v1.md

@@ -205,3 +205,10 @@ crashes after evidence publication, external test confirmation and byte-preservi
 output. The BUG-20 integration uses actual wowdiag/wowsrc data and simulated model
 decisions; it tests orchestration, not real model reasoning or discovery of the
 known fix. No paid/cloud model is called by these tests.
+
+Question resolution is idempotent: reconfirming an already resolved question
+does not invalidate an otherwise valid decision and needs no new evidence.
+Resolving any still-open question requires evidence references. Unknown question
+IDs invalidate the entire decision before assessments, tools or budget changes
+are applied. Mixing old confirmations with new resolutions follows the same
+rules; existing question history is preserved.

src/viano_bug_analysis/analysis/investigator.py

@@ -420,8 +420,11 @@ class Investigator:
         if next_action["kind"]=="reject" and update["confidence"] in {"supported","strongly_supported"}:
             raise InvestigationError("INVESTIGATION_CONTRADICTORY_UPDATE")
         questions={q["id"]:q for q in h["questions"]}
-        if (any(q not in questions or questions[q]["resolved"] for q in update["resolve_questions"])
-                or (update["resolve_questions"] and not update["evidence_refs"])):raise InvestigationError("INVESTIGATION_QUESTION")
+        # Reconfirming an already resolved question is an idempotent no-op.
+        # Only a new resolution needs evidence; unknown IDs remain invalid.
+        if (any(q not in questions for q in update["resolve_questions"])
+                or (any(not questions[q]["resolved"] for q in update["resolve_questions"])
+                    and not update["evidence_refs"])):raise InvestigationError("INVESTIGATION_QUESTION")
         if len(h["questions"])+len(update["add_questions"])>state["policy"]["max_questions_per_hypothesis"]:
             raise InvestigationError("INVESTIGATION_QUESTION_LIMIT")
         if any(text.casefold().strip() in {q["text"].casefold().strip() for q in h["questions"]} for text in update["add_questions"]):

tests/test_investigator.py

@@ -154,6 +154,48 @@ def test_question_updates_keep_history_and_require_evidence(tool_case):
     assert questions[0]["resolved"] and questions[1]["id"]=="Q0002" and not questions[1]["resolved"]
 
 
+@pytest.mark.parametrize('repeat_with_evidence',[False,True])
+def test_resolved_question_can_be_reconfirmed_without_blocking(tool_case,repeat_with_evidence):
+    def change(reply,context):
+        if not context['previous_result']:
+            return
+        h=context['hypotheses'][context['selected_hypothesis']]
+        reply['update']['resolve_questions']=['Q0001']
+        if not h['questions'][0]['resolved']:
+            reply['update']['add_questions']=['A later question requiring evidence']
+            reply['next']={'kind':'tool','operation':'source.read_context',
+                           'arguments':{'source_ref':'tool/code.cpp','start_line':1,'end_line':1}}
+        elif repeat_with_evidence:
+            # Mix the old confirmation with a genuinely new resolution.
+            reply['update']['resolve_questions'].append('Q0002')
+        else:
+            reply['update']['evidence_refs']=[]
+    result=run(Investigator(tool_case[0],gateway(LoopAdapter(change))))
+    assert result.status=='COMPLETED'
+    for h in state(result)['hypotheses'].values():
+        assert h['invalid_responses']==0
+        assert len(h['questions'])==2 and h['questions'][0]['resolved']
+        assert h['questions'][1]['resolved'] is repeat_with_evidence
+    snapshot=BudgetManager(tool_case[0]).snapshot(*CASE)
+    assert all(len(a['actions'])==2 for a in snapshot.state['accounts'].values())
+    assert PackageValidator().validate(result.package).valid
+
+
+@pytest.mark.parametrize('question',['Q0001','Q9999'])
+def test_new_or_unknown_resolution_rejected_atomically_without_evidence(tool_case,question):
+    def change(reply,context):
+        if context['previous_result']:
+            reply['update']['resolve_questions']=[question]
+            reply['update']['evidence_refs']=[]
+    loop=Investigator(tool_case[0],gateway(LoopAdapter(change)))
+    before=run(loop,steps=3)
+    budget=BudgetManager(tool_case[0]).snapshot(*CASE).state
+    result=asyncio.run(loop.step(*CASE))
+    assert result.status=='REJECTED' and result.code=='INVESTIGATION_QUESTION'
+    assert BudgetManager(tool_case[0]).snapshot(*CASE).state==budget
+    assert state(result)['hypotheses']['H1']['questions']==state(before)['hypotheses']['H1']['questions']
+
+
 def test_state_pointer_deletion_and_policy_change_do_not_restart(tool_case):
     loop=Investigator(tool_case[0],gateway(LoopAdapter()))
     first=run(loop,steps=1)