Update and refine the implementation roadmap

docs/roadmap/config.md

@@ -396,11 +396,12 @@ Supported fields:
 - `on_destination_newer`
 - `on_conflict`
 
-Recommended supported values:
+MVP supported values are intentionally limited by field:
 
-- `skip`
-- `replace`
-- `fail`
+- `on_destination_same`: `skip` or `fail`
+- `on_destination_older`: `replace` or `fail`
+- `on_destination_newer`: `skip` or `fail`
+- `on_conflict`: `fail`
 
 Recommended MVP defaults:
 
@@ -417,6 +418,7 @@ Safety rule:
 - `replace` must never perform broad deletion against a destination root.
 - `replace` may only operate within a resolved destination bundle path and should delete only files recorded in existing `.distributor.json.outputs` plus `.distributor.json` where practical.
 - Unmanaged non-empty destination paths fail in the MVP. Force or unmanaged overwrite configuration is deferred.
+- Broader replacement values, including replacing newer destinations or conflicts, are deferred to a later explicit force-overwrite stage.
 
 ## Path Mapping
 
@@ -574,5 +576,5 @@ Future notification policy should require:
 The following configuration ideas are intentionally outside the MVP:
 
 - warning-only digest mismatch handling;
-- unmanaged destination overwrite flags;
-- force replacement of destinations with different source ids.
+- unmanaged destination overwrite flags until the explicit force-overwrite roadmap stage;
+- force replacement of destinations with different source ids until the explicit force-overwrite roadmap stage.