refinement of upcoming tracks

conductor/tracks/session_insights_20260306/spec.md

@@ -1,21 +1,35 @@
 # Track Specification: Session Insights & Efficiency Scores (session_insights_20260306)
 
 ## Overview
-Token usage over time, cost projections, session summary with efficiency scores. Visualize session_logger data.
+Token usage over time, cost projections, session summary with efficiency scores.
 
-## Architectural Constraints
-- **Efficient Calculation**: Metrics MUST be calculated incrementally.
-- **Real-Time**: Updates SHOULD reflect current session state.
+## Current State Audit
+
+### Already Implemented
+- **`session_logger.py`**: Logs comms, tool calls, API hooks
+- **`ai_client.get_comms_log()`**: Returns API interaction history
+- **`cost_tracker.estimate_cost()`**: Cost calculation
+
+### Gaps to Fill
+- No token timeline visualization
+- No cost projection
+- No efficiency score calculation
 
 ## Functional Requirements
-- **Token Timeline**: Graph of token usage over session.
-- **Cost Projection**: Estimate remaining budget based on usage.
-- **Efficiency Score**: Calculate tokens-per-useful-change ratio.
-- **Session Summary**: Text summary of session metrics.
+- Token usage graph over session
+- Cost projection based on burn rate
+- Efficiency score (tokens per useful change)
+- Session summary text
+
+## Key Integration Points
+| File | Purpose |
+|-----|---------|
+| `src/session_logger.py` | Read session data |
+| `src/gui_2.py` | Timeline rendering |
 
 ## Acceptance Criteria
-- [ ] Token timeline renders.
-- [ ] Cost projection accurate.
-- [ ] Efficiency score calculated.
-- [ ] Summary displays key metrics.
-- [ ] Uses existing session_logger.
+- [ ] Token timeline renders
+- [ ] Cost projection calculated
+- [ ] Efficiency score shown
+- [ ] Summary displays key metrics
+- [ ] 1-space indentation