A1: S5F13-F18 exception recovery messages (E5 §9.5-9.7)

Catalog gains the recover-request / recover-complete / recover-abort
loop that closes E5's exception lifecycle.  Wire shapes:

  S5F13/F14  Exception Recover Request / Acknowledge
  S5F15/F16  Exception Recover Complete Notify / Acknowledge
  S5F17/F18  Exception Recover Abort Request / Acknowledge

Acks use the same AlarmAck byte already in use by S5F10/F12.  EXRESULT
on F15 is modelled as ASCII (the common case; vendor-specific richer
shapes are a YAML edit).

Round-trip tests cover all three pairs.  Server dispatch is left for a
later commit alongside the per-alarm AlarmStateMachine (Tranche C) —
this commit is wire-coverage only.

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

COMPLIANCE.md

@@ -172,6 +172,9 @@ YAML/handler extensions, not surgery):
 | S5F7 / S5F8      | H→E       | ✅     | catalog        | ✅ round-trip |
 | S5F9 / S5F10     | E→H       | ✅     | catalog        | ✅ round-trip (exception post) |
 | S5F11 / S5F12    | E→H       | ✅     | catalog        | ✅ round-trip (exception clear) |
+| S5F13 / S5F14    | H→E       | ✅     | catalog        | ✅ round-trip (exception recover request) |
+| S5F15 / S5F16    | E→H       | ✅     | catalog        | ✅ round-trip (exception recover complete) |
+| S5F17 / S5F18    | H→E       | ✅     | catalog        | ✅ round-trip (exception recover abort) |
 | S6F1 / S6F2      | E→H       | ✅     | catalog        | ✅ round-trip |
 | S6F11 / S6F12    | E→H       | ✅     | catalog        | ✅ round-trip + demo |
 | S6F23 / S6F24    | H→E       | ✅     | catalog        | ✅ round-trip + demo |

data/messages.yaml

@@ -725,6 +725,70 @@ messages:
     builder: s5f12_exception_clear_confirm
     body: {kind: scalar, item_type: BINARY_BYTE, enum: AlarmAck, param: ack}
 
+  # S5F13 / S5F14 — Exception Recover Request / Acknowledge (E5 §9.5).
+  # Host asks the equipment to execute a specific recovery action from
+  # the EXRECVRA list that the prior S5F9 advertised.  EXRECVRA on F13
+  # is a single action string, distinct from the list of allowed actions
+  # on F9.  F14 echoes ACKC5 as our AlarmAck byte.
+  - id: S5F13
+    stream: 5
+    function: 13
+    w: true
+    builder: s5f13_exception_recover_request
+    parser: parse_s5f13
+    body:
+      kind: list
+      struct_name: ExceptionRecoverRequest
+      fields:
+        - {name: exid,     shape: {kind: scalar, item_type: U4}}
+        - {name: exrecvra, shape: {kind: scalar, item_type: ASCII}}
+
+  - id: S5F14
+    stream: 5
+    function: 14
+    builder: s5f14_exception_recover_ack
+    body: {kind: scalar, item_type: BINARY_BYTE, enum: AlarmAck, param: ack}
+
+  # S5F15 / S5F16 — Exception Recover Complete Notify / Acknowledge
+  # (E5 §9.6).  Equipment signals that the recovery action requested by
+  # the matching S5F13 has finished; EXRESULT carries any structured
+  # outcome the equipment wishes to report (we model it as ASCII, which
+  # is the common case — vendor-specific richer shapes are a YAML edit).
+  - id: S5F15
+    stream: 5
+    function: 15
+    w: true
+    builder: s5f15_exception_recover_complete_notify
+    parser: parse_s5f15
+    body:
+      kind: list
+      struct_name: ExceptionRecoverComplete
+      fields:
+        - {name: exid,     shape: {kind: scalar, item_type: U4}}
+        - {name: exresult, shape: {kind: scalar, item_type: ASCII}}
+
+  - id: S5F16
+    stream: 5
+    function: 16
+    builder: s5f16_exception_recover_complete_ack
+    body: {kind: scalar, item_type: BINARY_BYTE, enum: AlarmAck, param: ack}
+
+  # S5F17 / S5F18 — Exception Recover Abort Request / Acknowledge
+  # (E5 §9.7).  Host aborts a recovery action currently in flight.
+  - id: S5F17
+    stream: 5
+    function: 17
+    w: true
+    builder: s5f17_exception_recover_abort_request
+    parser: parse_s5f17
+    body: {kind: scalar, item_type: U4, param: exid}
+
+  - id: S5F18
+    stream: 5
+    function: 18
+    builder: s5f18_exception_recover_abort_ack
+    body: {kind: scalar, item_type: BINARY_BYTE, enum: AlarmAck, param: ack}
+
   # =====================================================================
   # S6 — Data collection
   # =====================================================================

tests/test_messages.cpp

@@ -498,6 +498,48 @@ TEST_CASE("S5F11 / S5F12 exception clear round-trip") {
   CHECK(*ack_byte(s5f12_exception_clear_confirm(AlarmAck::Accept)) == 0);
 }
 
+TEST_CASE("S5F13 / S5F14 exception recover request round-trip") {
+  auto m = s5f13_exception_recover_request(42, "RETRY");
+  CHECK(m.stream == 5);
+  CHECK(m.function == 13);
+  CHECK(m.reply_expected);
+
+  auto parsed = parse_s5f13(m);
+  REQUIRE(parsed.has_value());
+  CHECK(parsed->exid == 42);
+  CHECK(parsed->exrecvra == "RETRY");
+
+  CHECK(*ack_byte(s5f14_exception_recover_ack(AlarmAck::Accept)) == 0);
+}
+
+TEST_CASE("S5F15 / S5F16 exception recover complete round-trip") {
+  auto m = s5f15_exception_recover_complete_notify(42, "OK");
+  CHECK(m.stream == 5);
+  CHECK(m.function == 15);
+  CHECK(m.reply_expected);
+
+  auto parsed = parse_s5f15(m);
+  REQUIRE(parsed.has_value());
+  CHECK(parsed->exid == 42);
+  CHECK(parsed->exresult == "OK");
+
+  CHECK(*ack_byte(s5f16_exception_recover_complete_ack(AlarmAck::Accept)) == 0);
+}
+
+TEST_CASE("S5F17 / S5F18 exception recover abort round-trip") {
+  auto m = s5f17_exception_recover_abort_request(42);
+  CHECK(m.stream == 5);
+  CHECK(m.function == 17);
+  CHECK(m.reply_expected);
+
+  // Scalar U4 parser returns the value directly.
+  auto exid = parse_s5f17(m);
+  REQUIRE(exid.has_value());
+  CHECK(*exid == 42);
+
+  CHECK(*ack_byte(s5f18_exception_recover_abort_ack(AlarmAck::Accept)) == 0);
+}
+
 TEST_CASE("S7F19 / S7F20 EPPD list") {
   auto req = s7f19_current_eppd_request();
   CHECK(req.stream == 7);