100%/A: S5F7/F8 list enabled alarms

Closes the small remaining hole in Alarm Management.  S5F7 is
header-only; S5F8 has the same wire shape as S5F6 (vector of
<L,3 <B ALCD> <U4 ALID> <A ALTX>>) but only includes alarms whose
enabled flag is set.  Codegen handles both as a list_of with
struct_name=AlarmListing; server pre-computes the per-row ALCD from
(severity_category, active state) before passing the rows in.

COMPLIANCE.md: Alarm Management Additional capability flips ✅.

Tests: 78 cases / 454 assertions.

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

data/messages.yaml

@@ -503,6 +503,30 @@ messages:
 
   # S5F6 is hand-written (per-row ALCD requires an active-callback API).
 
+  # S5F7 / S5F8 — List Enabled Alarms.  Same wire shape as S5F6 but only
+  # alarms with bit-7 of their stored "enabled" flag are returned.
+  - id: S5F7
+    stream: 5
+    function: 7
+    w: true
+    builder: s5f7_list_enabled_alarms_request
+
+  - id: S5F8
+    stream: 5
+    function: 8
+    builder: s5f8_list_enabled_alarms_data
+    parser: parse_s5f8
+    body:
+      kind: list_of
+      name: items
+      element:
+        kind: list
+        struct_name: AlarmListing
+        fields:
+          - {name: alcd, shape: {kind: scalar, item_type: BINARY_BYTE}}
+          - {name: alid, shape: {kind: scalar, item_type: U4}}
+          - {name: altx, shape: {kind: scalar, item_type: ASCII}}
+
   # =====================================================================
   # S6 — Data collection
   # =====================================================================