Clarify anchor-based mining model

docs/UNIVERSE-MODEL.md

@@ -197,6 +197,22 @@ Resource nodes are not construction sites.
 
 That is intentional so they can be spawned, depleted, despawned, and regenerated more freely than permanent infrastructure anchors.
 
+Resource nodes are strategic mining destinations.
+
+That means:
+
+- outside localspace, a miner travels to a resource-node anchor
+- inside that localspace, the miner chooses a concrete extractable target
+
+The concrete extractable target is a tactical mining concern, not a strategic travel identity.
+
+So:
+
+- travel uses `anchorId`
+- local extraction uses a localspace-level target such as a rock, cluster, or gas pocket
+
+Do not use a generic `NodeId` to mean both.
+
 ## Localspace
 
 `localspace` is the tactical simulation term and should be the only term used for this concept.
@@ -232,6 +248,16 @@ Localspace is where close simulation happens:
 - local logistics
 - tactical defense
 
+For mining specifically:
+
+- the destination localspace is chosen by anchor
+- the final extractable target is chosen only after the ship is inside that localspace
+
+This preserves the distinction between:
+
+- strategic travel to a mining site
+- tactical mining behavior inside that site
+
 Ships and constructions do not exist directly in system space. They exist in one localspace at a time unless they are explicitly traveling between anchors.
 
 ## Ship Placement