Gate settled anchor fallbacks by raw index

docs/architecture/stable-assistant-turn-anchor-phase0.md

@@ -309,9 +309,13 @@ must not compete with an anchor-owned turn.
 | Historical / non-anchor transcripts | No anchor owner is available. | Raw `content[]`, persisted `session.tool_calls`, role=`tool` rows, and partial tool-call snapshots continue to recover visible tool/prose history. | None. These paths remain until replay/runtime-journal coverage proves the same transcript shapes hydrate through anchors. |
 | Live reattach / session switch | `renderLiveAnchorActivityScene()` consumes the projected live scene, and session switch first attempts runtime-journal anchor scene restore. | Saved live DOM snapshots and `INFLIGHT` tool replay. | Snapshot fallback only runs when no usable live anchor scene can be rendered. |
 
-This matrix is an audit baseline, not permission to delete fallbacks. Fallback
-removal should wait for replay/runtime-journal parity tests that prove all
-supported settled transcript sources hydrate through anchors.
+This matrix is the current settled-render contract, backed by runtime-journal
+hydration parity and behavior-level renderer ownership coverage. Fallback paths
+are compatibility-only rebuilds for historical or genuinely non-anchor
+transcripts, and the renderer must gate them by explicit raw transcript indexes
+so object identity or duplicate message references cannot let fallback rows
+compete with an anchor-owned turn. Removing a compatibility path still requires
+new evidence that the supported transcript shape hydrates through anchors.
 
 ## Source Event Classification
 

static/ui.js

@@ -11773,6 +11773,14 @@ function _transparentStreamOrderedParts(message){
   }
   return hasText&&hasTool?ordered:null;
 }
+function _legacySettledFallbackHasToolMetadata(message){
+  if(!message||message.role!=='assistant'||message._anchor_activity_scene) return false;
+  return !!(
+    (Array.isArray(message.tool_calls)&&message.tool_calls.length>0)||
+    (Array.isArray(message._partial_tool_calls)&&message._partial_tool_calls.length>0)||
+    (Array.isArray(message.content)&&message.content.some(part=>part&&typeof part==='object'&&part.type==='tool_use'))
+  );
+}
 function _transparentOrderedDisplayText(text){
   return _stripWorkspaceDisplayPrefix(
     _stripAttachedFilesMarkerForDisplay(
@@ -12614,12 +12622,8 @@ function renderMessages(options){
   // tracking, or runs that didn't go through the normal streaming path), build
   // a display list from per-message tool_calls (OpenAI format) stored in each
   // assistant message. This covers the reload case described in issue #140.
-  const hasMessageToolMetadata=!S.busy&&Array.isArray(S.messages)&&S.messages.some(m=>
-    m&&m.role==='assistant'&&!anchorOwnedAssistantRawIdxs.has(S.messages.indexOf(m))&&(
-      (Array.isArray(m.tool_calls)&&m.tool_calls.length>0)||
-      (Array.isArray(m._partial_tool_calls)&&m._partial_tool_calls.length>0)||
-      (Array.isArray(m.content)&&m.content.some(p=>p&&typeof p==='object'&&p.type==='tool_use'))
-    )
+  const hasMessageToolMetadata=!S.busy&&Array.isArray(S.messages)&&S.messages.some((m,rawIdx)=>
+    !anchorOwnedAssistantRawIdxs.has(rawIdx)&&_legacySettledFallbackHasToolMetadata(m)
   );
   if(!S.busy && (hasMessageToolMetadata||!S.toolCalls||!S.toolCalls.length)){
     // Index tool outputs by tool_call_id / tool_use_id so the
@@ -12664,10 +12668,7 @@ function renderMessages(options){
       }
       if(m.role==='assistant'){
         if(anchorOwnedAssistantRawIdxs.has(rawIdx)) return;
-        const hasTopLevelToolCalls=Array.isArray(m.tool_calls)&&m.tool_calls.length>0;
-        const hasPartialToolCalls=Array.isArray(m._partial_tool_calls)&&m._partial_tool_calls.length>0;
-        const hasContentToolUse=Array.isArray(m.content)&&m.content.some(p=>p&&typeof p==='object'&&p.type==='tool_use');
-        if(hasTopLevelToolCalls||hasContentToolUse||hasPartialToolCalls) fallbackToolSources.push({m,rawIdx});
+        if(_legacySettledFallbackHasToolMetadata(m)) fallbackToolSources.push({m,rawIdx});
       }
     });
     const derived=[];

tests/test_anchor_fallback_ownership.py

@@ -264,7 +264,9 @@ def test_phase0_doc_records_settled_fallback_ownership_matrix():
     assert "| Settled Compact Worklog activity |" in doc
     assert "| Settled Transparent Stream activity |" in doc
     assert "| Historical / non-anchor transcripts |" in doc
-    assert "This matrix is an audit baseline, not permission to delete fallbacks." in doc
+    assert "This matrix is the current settled-render contract" in doc
+    assert "compatibility-only rebuilds" in doc
+    assert "explicit raw transcript indexes" in doc
 
 
 def test_function_extractor_handles_nested_template_literal_interpolation():
@@ -404,6 +406,9 @@ def test_render_messages_keeps_anchor_owned_turn_out_of_legacy_activity_rebuilds
 
     render_source = _function_source(_ui_js(), "renderMessages")
     transparent_source = _function_source(_ui_js(), "_transparentStreamOrderedParts")
+    legacy_metadata_source = _function_source(
+        _ui_js(), "_legacySettledFallbackHasToolMetadata"
+    )
     script = textwrap.dedent(
         f"""
         class FakeClassList {{
@@ -677,6 +682,7 @@ def test_render_messages_keeps_anchor_owned_turn_out_of_legacy_activity_rebuilds
         }}
 
         eval({json.dumps(transparent_source)});
+        eval({json.dumps(legacy_metadata_source)});
         eval({json.dumps(render_source)});
 
         const toolResult = {{ role: 'tool', tool_call_id: 'toolu_1', content: 'tool result' }};
@@ -767,11 +773,58 @@ def test_render_messages_keeps_anchor_owned_turn_out_of_legacy_activity_rebuilds
           sToolCalls: S.toolCalls.length,
         }};
 
+        elements.msgInner = new FakeElement('div');
+        legacyCards = [];
+        const duplicateAnchorTool = {{ type: 'tool_use', id: 'toolu_anchor_dup', name: 'terminal', input: {{ cmd: 'anchor' }} }};
+        const duplicateHistoricalTool = {{ type: 'tool_use', id: 'toolu_hist_dup', name: 'terminal', input: {{ cmd: 'history' }} }};
+        const duplicateAnchorCall = {{
+          id: 'toolu_anchor_dup',
+          function: {{ name: 'terminal', arguments: '{{"cmd":"anchor"}}' }},
+        }};
+        const duplicateAnchorOwned = {{
+          role: 'assistant',
+          content: [{{ type: 'text', text: 'Duplicate answer' }}, duplicateAnchorTool],
+          tool_calls: [duplicateAnchorCall],
+          _anchor_activity_scene: {{
+            version: 'activity_scene_v1',
+            activity_rows: [{{ id: 'row-dup', kind: 'tool', role: 'tool', tool: {{ name: 'terminal' }} }}],
+            final_answer: 'Duplicate answer',
+          }},
+        }};
+        const duplicateHistorical = {{
+          role: 'assistant',
+          content: [{{ type: 'text', text: 'Duplicate answer' }}, duplicateHistoricalTool],
+        }};
+        S = {{
+          session: {{
+            session_id: 's4',
+            tool_calls: [{{ tid: 'toolu_hist_dup', snippet: 'historical persisted result' }}],
+          }},
+          messages: [
+            {{ role: 'user', content: 'anchor turn' }},
+            duplicateAnchorOwned,
+            {{ role: 'user', content: 'historical turn' }},
+            duplicateHistorical,
+            toolResult,
+          ],
+          toolCalls: [{{ tid: 'toolu_anchor_dup', assistant_msg_idx: 1, name: 'terminal', snippet: 'anchor session fallback' }}],
+          busy: false,
+        }};
+        renderMessages();
+        const duplicateReferenceSummary = {{
+          anchorGroups: elements.msgInner.querySelectorAll('[data-anchor-settled-scene-owner]').length,
+          legacyGroups: elements.msgInner.querySelectorAll('[data-legacy-fallback-owner]').length,
+          legacyRows: elements.msgInner.querySelectorAll('.tool-card-row').length,
+          legacyCards,
+          sToolCalls: S.toolCalls.length,
+        }};
+
         console.log(JSON.stringify({{
           selectorSanity,
           anchorSummary,
           historicalSummary,
           rawHistoricalSummary,
+          duplicateReferenceSummary,
         }}));
         """
     )
@@ -810,6 +863,15 @@ def test_render_messages_keeps_anchor_owned_turn_out_of_legacy_activity_rebuilds
     assert raw_snippets["partial_1"] == "partial result"
     assert raw_snippets["content_1"] == "persisted content result"
 
+    duplicate_cards = result["duplicateReferenceSummary"]["legacyCards"]
+    assert result["duplicateReferenceSummary"]["anchorGroups"] == 1
+    assert result["duplicateReferenceSummary"]["legacyGroups"] == 1
+    assert result["duplicateReferenceSummary"]["legacyRows"] >= 1
+    assert result["duplicateReferenceSummary"]["sToolCalls"] >= 1
+    assert {card["tid"] for card in duplicate_cards} == {"toolu_hist_dup"}
+    assert "toolu_anchor_dup" not in {card["tid"] for card in duplicate_cards}
+    assert duplicate_cards[0]["snippet"] == "historical persisted result"
+
 
 def test_settled_legacy_tool_rebuild_excludes_anchor_owned_turns():
     render = _function_body(_ui_js(), "renderMessages")
@@ -821,7 +883,9 @@ def test_settled_legacy_tool_rebuild_excludes_anchor_owned_turns():
     source_collect = render.index("fallbackToolSources.push({m,rawIdx});")
 
     assert set_decl < collect_segments < metadata_scan < fallback_sources < source_collect
-    assert "!anchorOwnedAssistantRawIdxs.has(S.messages.indexOf(m))" in render
+    assert "S.messages.indexOf(m)" not in render
+    assert "S.messages.some((m,rawIdx)=>" in render
+    assert "!anchorOwnedAssistantRawIdxs.has(rawIdx)&&_legacySettledFallbackHasToolMetadata(m)" in render
     assert "if(anchorOwnedAssistantRawIdxs.has(rawIdx)) return;" in render
 
 

tests/test_issue401.py

@@ -86,8 +86,9 @@ def test_rendermessages_treats_partial_toolcall_assistants_as_visible():
 
 def test_rendermessages_rebuilds_tool_cards_from_partial_tool_calls():
     """Fallback reconstruction should include private `_partial_tool_calls` rows."""
-    assert "const hasPartialToolCalls=Array.isArray(m._partial_tool_calls)&&m._partial_tool_calls.length>0;" in UI_JS
-    assert "if(hasTopLevelToolCalls||hasContentToolUse||hasPartialToolCalls) fallbackToolSources.push({m,rawIdx});" in UI_JS
+    assert "function _legacySettledFallbackHasToolMetadata(message)" in UI_JS
+    assert "Array.isArray(message._partial_tool_calls)&&message._partial_tool_calls.length>0" in UI_JS
+    assert "if(_legacySettledFallbackHasToolMetadata(m)) fallbackToolSources.push({m,rawIdx});" in UI_JS
     assert "if(Array.isArray(m._partial_tool_calls)){" in UI_JS
     assert "tc.snippet||tc.result||tc.output||tc.preview" in UI_JS
     assert "done:true" in UI_JS

tests/test_live_to_final_anchor_visible_order.py

@@ -771,7 +771,12 @@ def test_anchor_owned_settled_turn_skips_legacy_worklog_rebuild():
     assert "anchorOwnedAssistantRawIdxs.add(idx)" in render
     assert "if(anchorOwnedAssistantRawIdxs.has(aIdx)) continue;" in render
     assert "if(anchorOwnedAssistantRawIdxs.has(rawIdx)) return;" in render
-    assert "!anchorOwnedAssistantRawIdxs.has(S.messages.indexOf(m))" in render
+    assert "S.messages.indexOf(m)" not in render
+    assert "S.messages.some((m,rawIdx)=>" in render
+    assert (
+        "!anchorOwnedAssistantRawIdxs.has(rawIdx)"
+        "&&_legacySettledFallbackHasToolMetadata(m)"
+    ) in render
 
 
 def test_transparent_stream_renders_persisted_anchor_scene_after_reload():