# Runtime Timeline API

## Module
Scanner

## Status
IMPLEMENTED

## Description
Provides a chronological timeline of runtime observations (RuntimeTimeline model, TimelineBuilder, RuntimePosture enum) with an API endpoint. Distinct from "Runtime Reachability Collection" which is about gathering data, not the timeline visualization API.

## Implementation Details
- **Timeline Model**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.Native/RuntimeCapture/Timeline/RuntimeTimeline.cs` - `RuntimeTimeline` model representing a chronological sequence of runtime observations with `RuntimePosture` classification
- **Timeline Builder**:
  - `src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.Native/RuntimeCapture/Timeline/TimelineBuilder.cs` - `TimelineBuilder` constructs timeline instances from raw runtime observations, ordering events chronologically and computing posture
- **Tests**:
  - `src/Scanner/__Tests/StellaOps.Scanner.Analyzers.Native.Library.Tests/RuntimeCapture/Timeline/TimelineBuilderTests.cs` - Unit tests for timeline construction and posture computation

## E2E Test Plan
- [ ] Build a runtime timeline from a set of native runtime observations and verify events are ordered chronologically
- [ ] Verify the `RuntimePosture` enum correctly classifies the overall runtime posture based on observation patterns
- [ ] Verify timeline entries include observation timestamps, source types, and observation counts
- [ ] Submit runtime observations over time and verify the timeline reflects the temporal progression accurately
- [ ] Verify the timeline API endpoint returns the timeline in a serializable format with correct pagination support