feat(blocks): wire Rotate and Flip actions and saved reference grips

Author Rotate actions against Rotation parameters and Flip actions against Flip
parameters through the existing palette, BACTION selection flow and native
evaluation graph. Keep markers selectable and editable in BEDIT.

Rotation grips accept a new direction at the original radius. Flip grips toggle
immediately. Evaluate both from immutable definition geometry in Test Block and
independent drawing references, preserving per-INSERT angle/state caches across
DWG/DXF saves and COPY. Undo/redo includes the native state and representation.
Accept parameter names containing spaces at the action parameter prompt.

332 block regressions pass (6 existing opt-in checks ignored), including native
binding/marker roundtrips, composed rotation/flip, repeated reversible toggles,
COPY isolation, viewport mouse interactions, history and saved-reference reopen.
Custom base modes, constrained/chained evaluation and parameter-target actions
remain unsupported; Rotate currently binds Rotation parameters.

src/command.rs

@@ -1534,7 +1534,7 @@ pub enum CmdResult {
         document: u64,
         definition: Handle,
         parameter: Handle,
-        position: DVec3,
+        value: crate::scene::block_actions::Value,
     },
     /// Place or relocate a Basepoint, or place a Lookup parameter.
     PlaceBlockSingleParameter {