VAPI-4041: send Twilio's action params from /bw/continue

AGENTS.md

@@ -106,9 +106,26 @@ Translation is a fixed rulebook (`src/matrix/twilio-voice.json`), not a guess.
   - `Reject` — maps to `Hangup`, but Bandwidth answers before hanging up, so the
     caller may be billed for a short call.
   - `Dial` — `Number`/`Sip` nouns map to `Transfer`, `Conference` noun maps to
-    `Conference`; the `Queue` and `Client` nouns are unsupported, and deep Dial
-    semantics (`answerOnBridge`, child-call status propagation) are not
-    replicated.
+    `Conference`; the `Queue` and `Client` nouns are unsupported, and
+    `answerOnBridge` is not replicated. The Dial `action` receives Twilio's
+    `DialCallStatus` and `DialBridged` mapped from Bandwidth's transfer result;
+    `DialCallSid` and `DialCallDuration` come from the dialed leg's
+    `transferDisconnect` event, which the translator receives at
+    `/bw/transfer-leg` and joins to the parent's `transferComplete` (waiting up
+    to `transferLegWaitMs`, default 400 ms, since Bandwidth documents no
+    ordering between the two). Each Dial's legs are keyed to that Dial, and for
+    a multi-number Dial the leg that answered is reported, not the cancelled
+    ones. As on Twilio, a caller hangup during the
+    transfer ends the session without requesting the action.
+  - `Gather` — a Gather that ends with no digits or speech does **not** request
+    the action (Twilio semantics): the translator remembers each call's last
+    TwiML document and re-translates the verbs after that Gather. Set
+    `actionOnEmptyResult="true"` to request the action with `Digits=""` instead.
+    On a translator instance that has not seen the document (restart, second
+    replica) the action is requested as a fallback.
+  - `Record` — the `action` receives `RecordingUrl`, `RecordingSid`, and
+    `RecordingDuration` from Bandwidth's `recordComplete`; Bandwidth's event has
+    no equivalent of Twilio's `Digits` (the key that stopped the recording).
   - `Start` — the `Transcription` noun maps to `StartTranscription`; the
     `Siprec` and `VirtualAgent` nouns are unsupported.
   - `Refer` — Bandwidth only honors `Refer` on inbound SIP URI calls, so a PSTN

src/matrix/twilio-voice.json

@@ -29,7 +29,11 @@
       "notes": "DTMF and speech both supported. Per dev.bandwidth.com, BW Gather input accepts dtmf/speech/dtmf_speech.",
       "docsUrl": "https://dev.bandwidth.com/docs/voice/programmable-voice/bxml/gather",
       "attributes": {
-        "action": { "bxml": "gatherUrl", "status": "supported" },
+        "action": {
+          "bxml": "gatherUrl",
+          "status": "supported",
+          "notes": "No digits or speech does not request the action; the verbs after the Gather run instead (Twilio semantics). actionOnEmptyResult=\"true\" requests the action with Digits=\"\"."
+        },
         "numDigits": { "bxml": "maxDigits", "status": "supported" },
         "timeout": { "bxml": "firstDigitTimeout", "status": "supported" },
         "finishOnKey": { "bxml": "terminatingDigits", "status": "supported" },
@@ -72,7 +76,11 @@
       "notes": "Recording callback payloads differ; translator normalizes.",
       "docsUrl": "https://dev.bandwidth.com/docs/voice/bxml/record",
       "attributes": {
-        "action": { "bxml": "recordCompleteUrl", "status": "supported" },
+        "action": {
+          "bxml": "recordCompleteUrl",
+          "status": "supported",
+          "notes": "The callback carries RecordingUrl, RecordingSid, RecordingDuration. Bandwidth's event has no equivalent of Twilio's Digits."
+        },
         "recordingStatusCallback": { "bxml": "recordingAvailableUrl", "status": "supported", "notes": "Async 'recording ready' webhook. Translator receives the BW recordingAvailableUrl event, reshapes it into Twilio recordingStatusCallback params, and forwards it; RecordingUrl points back at the translator's recording facade. recordingStatusCallbackMethod=GET is not honored (forwarded via POST)." },
         "maxLength": { "bxml": "maxDuration", "status": "supported" },
         "finishOnKey": { "bxml": "terminatingDigits", "status": "supported" },
@@ -83,12 +91,16 @@
     "Dial": {
       "bxml": "Transfer",
       "status": "partial",
-      "notes": "Number/Sip nouns map to Transfer; Conference noun maps to Conference; Queue and Client nouns are unsupported. Deep Dial semantics (answerOnBridge, child-call status propagation) are not replicated in P0. When the record attribute is set to a recording-enabled value, a BW StartRecording verb is emitted immediately before the Transfer. Dual-channel variants (record-from-answer-dual, record-from-ringing-dual) emit StartRecording with multiChannel=true.",
+      "notes": "Number/Sip nouns map to Transfer; Conference noun maps to Conference; Queue and Client nouns are unsupported. answerOnBridge is not replicated. The Dial action receives DialCallStatus and DialBridged mapped from Bandwidth's transfer result, and DialCallSid/DialCallDuration from the dialed leg's transferDisconnect event when it has arrived. When the record attribute is set to a recording-enabled value, a BW StartRecording verb is emitted immediately before the Transfer. Dual-channel variants (record-from-answer-dual, record-from-ringing-dual) emit StartRecording with multiChannel=true.",
       "docsUrl": "https://dev.bandwidth.com/docs/voice/bxml/transfer",
       "attributes": {
         "callerId": { "bxml": "transferCallerId", "status": "supported" },
         "timeout": { "bxml": "callTimeout", "status": "supported" },
-        "action": { "bxml": "transferCompleteUrl", "status": "supported" },
+        "action": {
+          "bxml": "transferCompleteUrl",
+          "status": "supported",
+          "notes": "The callback carries DialCallStatus, DialBridged, and (from the dialed leg's transferDisconnect) DialCallSid and DialCallDuration. As on Twilio, a caller hangup during the transfer does not request the action."
+        },
         "record": {
           "bxml": "StartRecording",
           "status": "partial",