Clarify host readiness when game files or runtime are missing

docs/native-hosts.md

@@ -23,7 +23,10 @@ the agent owns local execution and its durable operation journal.
    no separate DLC declaration. Uploading also works before enrolling any host.
 5. Cache the published version on each destination host. Wait for verification.
    Hosts report connection and readiness separately; deployment also checks the
-   particular library, image, capacity and ports you selected.
+   particular library, image, capacity and ports you selected. A connected host
+   missing content shows **Needs runtime** or **Needs game files**; these require
+   setup rather than waiting for an automatic preparation step. **Ready** means
+   it has both a runtime image and a verified library available.
 6. Launch a server or collection. Select the host, immutable game-file version(s)
    and runtime image. EC selects lobby IDs and reserves UDP/TCP ports atomically.
    Saved Plutonium server keys remain associated with their exact server names.