Feature/memory pr (#889)

* feat: multi-turn context and conversation arc memory

PR 2E - Section 2.9, 2.10:
- Add multiTurnContext.ts with turn tracking and state preservation
- Add conversationArc.ts with goal/decision/milestone tracking
- Wire into query.ts after tool execution
- Feature-flags: MULTI_TURN_CONTEXT, CONVERSATION_ARC
- Add comprehensive tests (22 passing)

* feat(memory): resolve review blockers and integrate native Knowledge Graph into Conversation Arcs

- Fix: Extract text from production block arrays in phase detector\n- Fix: Ensure proper turn segmentation in query loop\n- Fix: Respect options in multi-turn context tracker\n- Feat: Add native Knowledge Graph (Entities/Relations) to ConversationArc architecture\n- Test: Comprehensive test suite for all fixes and new graph features

* test(perf): add automated performance benchmarks for Knowledge Graph extraction and summary

---------

Co-authored-by: LifeJiggy <Bloomtonjovish@gmail.com>

src/query.ts

@@ -252,6 +252,12 @@ async function* queryLoop(
   | ToolUseSummaryMessage,
   Terminal
 > {
+  // Start a new turn for multi-turn context tracking
+  if (feature('MULTI_TURN_CONTEXT')) {
+    const { startNewTurn } = await import('./utils/multiTurnContext.js')
+    startNewTurn()
+  }
+
   // Immutable params — never reassigned during the query loop.
   const {
     systemPrompt,
@@ -1516,6 +1522,28 @@ async function* queryLoop(
     }
     queryCheckpoint('query_tool_execution_end')
 
+    // Track multi-turn context after tool execution
+    if (feature('MULTI_TURN_CONTEXT')) {
+      const { addMessageToTurn, addToolCallToTurn } = await import(
+        './utils/multiTurnContext.js'
+      )
+      addMessageToTurn(assistantMessage)
+      for (const toolUse of toolUseBlocks) {
+        addToolCallToTurn({
+          id: toolUse.id,
+          name: toolUse.name,
+          input: toolUse.input as Record<string, unknown>,
+          timestamp: Date.now(),
+        })
+      }
+    }
+
+    // Update conversation arc phase
+    if (feature('CONVERSATION_ARC')) {
+      const { updateArcPhase } = await import('./utils/conversationArc.js')
+      updateArcPhase([assistantMessage])
+    }
+
     // Generate tool use summary after tool batch completes — passed to next recursive call
     let nextPendingToolUseSummary:
       | Promise<ToolUseSummaryMessage | null>