Document MVP persistence limitations

AGRARIAN_DEVELOPMENT_ROADMAP.md

@@ -785,7 +785,11 @@ Target deliverable: A small group can join a server, spawn into one biome, gathe
 - [x] Add recovery plan for corrupted save. Added
   `Docs/Ops/PersistenceSaveRecoveryPlan.md` covering suspect-save symptoms,
   backup restore steps, failed-backup fallback, and current MVP limitations.
-- [ ] Document persistence limitations.
+- [x] Document persistence limitations. Added an MVP limitations section to
+  `Docs/PersistenceDesignDocument.md` covering file-based saves, missing
+  database/account binding, migration limits, corrupted-save validation,
+  container actor capture, offline simulation, cross-server persistence,
+  external backup replication, UI, and pre-MVP save compatibility.
 
 ## 0.1.N MVP UI And UX
 

Docs/PersistenceDesignDocument.md

@@ -479,6 +479,27 @@ stop the server, preserve the suspect save, restore the newest timestamped
 backup, restart, validate the world, and only then allow a new manual/admin
 save.
 
+## MVP Persistence Limitations
+
+Version 0.1.M persistence is intentionally file-based and MVP-scoped.
+
+Current limitations:
+
+- no database-backed world state yet;
+- no account-provider identity binding yet;
+- no save migration framework beyond simple versioned records;
+- no automated corrupted-save validator yet;
+- no placed-container actor capture yet, only a reserved container save schema;
+- no full offline player simulation or family/generational simulation yet;
+- no cross-server persistence or shard transfer yet;
+- no external backup replication unless VM/project backup jobs include
+  `Saved/SaveGames`;
+- no player-facing save/load UI yet;
+- no compatibility guarantee for pre-MVP experimental save files.
+
+These limits are acceptable for the first playable MVP as long as they remain
+visible in handoffs, investor/demo notes, and release checklists.
+
 ## Testing Gates
 
 Minimum persistence smoke test:

Scripts/verify_persistence_limitations.py

@@ -0,0 +1,43 @@
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+
+EXPECTED = {
+    ROOT / "Docs" / "PersistenceDesignDocument.md": [
+        "## MVP Persistence Limitations",
+        "no database-backed world state yet",
+        "no account-provider identity binding yet",
+        "no save migration framework",
+        "no automated corrupted-save validator yet",
+        "no placed-container actor capture yet",
+        "no full offline player simulation or family/generational simulation yet",
+        "no cross-server persistence or shard transfer yet",
+        "no external backup replication",
+        "no player-facing save/load UI yet",
+        "no compatibility guarantee for pre-MVP experimental save files",
+    ],
+    ROOT / "AGRARIAN_DEVELOPMENT_ROADMAP.md": [
+        "[x] Document persistence limitations.",
+        "`Docs/PersistenceDesignDocument.md`",
+        "pre-MVP save compatibility",
+    ],
+}
+
+
+def main() -> None:
+    missing = []
+    for path, snippets in EXPECTED.items():
+        text = path.read_text(encoding="utf-8")
+        for snippet in snippets:
+            if snippet not in text:
+                missing.append(f"{path.relative_to(ROOT)}: {snippet}")
+
+    if missing:
+        raise RuntimeError("Persistence limitations verification failed: " + "; ".join(missing))
+
+    print("PASS: MVP persistence limitations are documented.")
+
+
+if __name__ == "__main__":
+    main()