Clarify that storage grows while compute is fixed

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: kcmartin

src/content/docs/concepts/lifecycle.mdx

@@ -69,9 +69,9 @@ Each Sprite runs with:
 
 - **8 vCPUs**
 - **4 GB RAM**
-- **100 GB storage**
+- **100 GB storage** (grows automatically)
 
-This configuration is fixed. One size keeps things simple.
+Compute is fixed. One size keeps things simple.
 
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