feat: Add token speed widgets (InputSpeed, OutputSpeed, TotalSpeed) (#141)

* Add token speed widgets (InputSpeed, OutputSpeed, TotalSpeed)

- Add SpeedMetrics type for tracking token throughput
- Implement speed calculation utilities in speed-metrics.ts
- Add InputSpeed, OutputSpeed, TotalSpeed widgets
- Extend jsonl.ts to extract timing data for speed calculation
- Inject speedMetrics into RenderContext for widget access
- Add unit tests for speed widgets

* Add widget-gated subagent speed aggregation with parallel reads

* Fix subagent speed parsing for session-directory transcript layout

* Consolidate speed windows into core speed widgets

* Bump to v2.2.0 and document new speed widgets

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Co-authored-by: Matthew Breedlove <sirmalloc@gmail.com>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ccstatusline",
-  "version": "2.1.10",
+  "version": "2.2.0",
   "description": "A customizable status line formatter for Claude Code CLI",
   "module": "src/ccstatusline.ts",
   "type": "module",