tui: Fix differential rendering to preserve scrollback buffer

- renderDifferential now correctly handles content that exceeds viewport
- When changes are above viewport, do full re-render with scrollback clear
- When changes are in viewport, do partial re-render from change point
- All tests pass, correctly preserves 100 items in scrollback
- Issue: Still re-renders too much (entire tail from first change)

packages/pods/package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@mariozechner/pi",
-	"version": "0.5.7",
+	"version": "0.5.8",
 	"description": "CLI tool for managing vLLM deployments on GPU pods",
 	"type": "module",
 	"bin": {
@@ -34,7 +34,7 @@
 		"node": ">=20.0.0"
 	},
 	"dependencies": {
-		"@mariozechner/pi-agent": "^0.5.7",
+		"@mariozechner/pi-agent": "^0.5.8",
 		"chalk": "^5.5.0"
 	},
 	"devDependencies": {}