N: E39 generic ObjectService — S14F1/F2 GetAttr + S14F3/F4 SetAttr

The catalog had S14F9/F10 / F11/F12 specialized for E94 ControlJob;
this commit adds the generic E14 attribute access pair, the most-
queried half of the E39 surface area, backed by the CemObjectStore.

  S14F1 / F2  GetAttr  — OBJSPEC + OBJTYPE + ATTRID list ->
                         (ATTRID, VALUE) pairs + OBJACK
  S14F3 / F4  SetAttr  — same addressing, applies ATTRID/VALUE pairs,
                         reply echoes stored values + OBJACK

Server dispatches both into the CemObjectStore added in tranche G.
OBJTYPE validation is case-sensitive against the CemObjectType name
(Equipment / Subsystem / IODevice / Module / MaterialLocation).
Unknown objects return Denied_UnknownObject; type mismatches return
Denied_InvalidAttribute.

The shared AttrValue struct is declared external_struct: true on
F3/F4 so both directions share the same C++ type.

Two round-trip tests cover both pairs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

data/messages.yaml

@@ -1407,6 +1407,93 @@ messages:
   # generic ATTRIBUTES list specialized.
   # =====================================================================
 
+  # S14F1 / F2 — GetAttr (generic).  E39/E14 ObjectService form: host
+  # requests one or more attribute values from a named object.  OBJSPEC
+  # is the dotted path through the CEM tree, OBJTYPE is the expected
+  # type (validated by the equipment), ATTRID is a list of names.
+  # Reply carries the values in the same order, plus an OBJACK code.
+  - id: S14F1
+    stream: 14
+    function: 1
+    w: true
+    builder: s14f1_get_attr
+    parser: parse_s14f1
+    body:
+      kind: list
+      struct_name: GetAttrRequest
+      fields:
+        - {name: objspec, shape: {kind: scalar, item_type: ASCII}}
+        - {name: objtype, shape: {kind: scalar, item_type: ASCII}}
+        - name: attrids
+          shape: {kind: list_of, element: {kind: scalar, item_type: ASCII}}
+
+  - id: S14F2
+    stream: 14
+    function: 2
+    builder: s14f2_get_attr_data
+    parser: parse_s14f2
+    body:
+      kind: list
+      struct_name: GetAttrReply
+      fields:
+        - name: attrs
+          shape:
+            kind: list_of
+            element:
+              kind: list
+              struct_name: AttrValue
+              fields:
+                - {name: attrid, shape: {kind: scalar, item_type: ASCII}}
+                - {name: value,  shape: {kind: scalar, item_type: ITEM}}
+        - {name: ack, shape: {kind: scalar, item_type: BINARY_BYTE, enum: ObjectAck}}
+
+  # S14F3 / F4 — SetAttr (generic).  Same OBJSPEC/OBJTYPE addressing as
+  # GetAttr; body carries (ATTRID, VALUE) pairs the equipment applies
+  # in order.  Reply echoes whatever the equipment now has.
+  - id: S14F3
+    stream: 14
+    function: 3
+    w: true
+    builder: s14f3_set_attr
+    parser: parse_s14f3
+    body:
+      kind: list
+      struct_name: SetAttrRequest
+      fields:
+        - {name: objspec, shape: {kind: scalar, item_type: ASCII}}
+        - {name: objtype, shape: {kind: scalar, item_type: ASCII}}
+        - name: attrs
+          shape:
+            kind: list_of
+            element:
+              kind: list
+              struct_name: AttrValue
+              external_struct: true
+              fields:
+                - {name: attrid, shape: {kind: scalar, item_type: ASCII}}
+                - {name: value,  shape: {kind: scalar, item_type: ITEM}}
+
+  - id: S14F4
+    stream: 14
+    function: 4
+    builder: s14f4_set_attr_ack
+    parser: parse_s14f4
+    body:
+      kind: list
+      struct_name: SetAttrReply
+      fields:
+        - name: attrs
+          shape:
+            kind: list_of
+            element:
+              kind: list
+              struct_name: AttrValue
+              external_struct: true
+              fields:
+                - {name: attrid, shape: {kind: scalar, item_type: ASCII}}
+                - {name: value,  shape: {kind: scalar, item_type: ITEM}}
+        - {name: ack, shape: {kind: scalar, item_type: BINARY_BYTE, enum: ObjectAck}}
+
   # S14F9 / F10 — CreateObject (CJ).  Host asks the equipment to bring
   # a new ControlJob into existence and registers the list of PJs it
   # contains; the CJ starts in CJ-QUEUED.