[Pather] fix port rename/deletion tracking

masque/builder/pather.py

@@ -228,7 +228,17 @@ class Pather(PortList):
     @logged_op(lambda args: list(args['mapping'].keys()))
     def rename_ports(self, mapping: dict[str, str | None], overwrite: bool = False) -> Self:
         self.pattern.rename_ports(mapping, overwrite)
-        renamed: dict[str, list[RenderStep]] = {vv: self.paths.pop(kk) for kk, vv in mapping.items() if kk in self.paths and vv is not None}
+        renamed: dict[str, list[RenderStep]] = {}
+        for kk, vv in mapping.items():
+            if kk not in self.paths:
+                continue
+            steps = self.paths.pop(kk)
+            # Preserve deferred geometry even if the live port is deleted.
+            # `render()` can still materialize the saved steps using their stored start/end ports.
+            # Current semantics intentionally keep deleted ports' queued steps under the old key,
+            # so if a new live port later reuses that name it does not retarget the old geometry;
+            # the old and new routes merely share a render bucket until `render()` consumes them.
+            renamed[kk if vv is None else vv] = steps
         self.paths.update(renamed)
         return self
 
@@ -789,6 +799,9 @@ class PortPather:
     #
     # Delegate to port
     #
+    # These mutate only the selected live port state. They do not rewrite already planned
+    # RenderSteps, so deferred geometry remains as previously planned and only future routing
+    # starts from the updated port.
     def set_ptype(self, ptype: str) -> Self:
         for port in self.ports:
             self.pather.pattern[port].set_ptype(ptype)
@@ -865,8 +878,7 @@ class PortPather:
 
     def drop(self) -> Self:
         """ Remove selected ports from the pattern and the PortPather. """
-        for pp in self.ports:
-            del self.pather.pattern.ports[pp]
+        self.pather.rename_ports({pp: None for pp in self.ports})
         self.ports = []
         return self
 
@@ -880,7 +892,7 @@ class PortPather:
         if name is None:
             self.drop()
             return None
-        del self.pather.pattern.ports[name]
+        self.pather.rename_ports({name: None})
         self.ports = [pp for pp in self.ports if pp != name]
         return self