🌿 ✨ [Scheduled] Update API Spec (#49)

* feat(openapi): add Langfuse credential support and new voice IDs

This commit adds support for Langfuse credentials, including the required fields (`provider`, `publicKey`, `apiKey`, `apiUrl`) and the unique identifiers (`id` and `orgId`). It also introduces new voice IDs: `ash`, `ballad`, `coral`, `sage`, and `verse`, which are exclusive to the `gpt-4o-realtime-preview-2024-10-01` model.

* feat(voice): add support for voice provider fallbacks and increase timeouts

* fix(fern/apis/api/openapi.json): Updated openapi.json with new transfer mode and SIP header support

This commit introduces a new transfer mode, "blind-transfer-add-summary-to-sip-header", which adds a SIP header with a call summary during a blind transfer. It also adds a new "sipHeaders" object to allow custom headers during a transfer call. Additionally, a new Azure region, "uaenorth", has been added to the list of supported regions.

* fix(fern/apis/api/openapi.json): update transfer mode descriptions and remove unused sipHeaders property

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Co-authored-by: fern-api[bot] <115122769+fern-api[bot]@users.noreply.github.com>

fern/apis/api/openapi.json

@@ -4186,10 +4186,9 @@
         "properties": {
           "mode": {
             "type": "string",
-            "description": "This configures how transfer is executed and the experience of the destination party receiving the call.\n\nUsage:\n- `blind-transfer`: The assistant forwards the call to the destination without any message or summary.\n- `blind-transfer-add-summary-to-sip-header`: The assistant forwards the call to the destination and adds a SIP header X-Transfer-Summary to the call to include the summary.\n- `warm-transfer-say-message`: The assistant dials the destination, delivers the `message` to the destination party, connects the customer, and leaves the call.\n- `warm-transfer-say-summary`: The assistant dials the destination, provides a summary of the call to the destination party, connects the customer, and leaves the call.\n- `warm-transfer-wait-for-operator-to-speak-first-and-then-say-message`: The assistant dials the destination, waits for the operator to speak, delivers the `message` to the destination party, and then connects the customer.\n- `warm-transfer-wait-for-operator-to-speak-first-and-then-say-summary`: The assistant dials the destination, waits for the operator to speak, provides a summary of the call to the destination party, and then connects the customer.\n\n@default 'blind-transfer'",
+            "description": "This configures how transfer is executed and the experience of the destination party receiving the call.\n\nUsage:\n- `blind-transfer`: The assistant forwards the call to the destination without any message or summary.\n- `warm-transfer-say-message`: The assistant dials the destination, delivers the `message` to the destination party, connects the customer, and leaves the call.\n- `warm-transfer-say-summary`: The assistant dials the destination, provides a summary of the call to the destination party, connects the customer, and leaves the call.\n- `warm-transfer-wait-for-operator-to-speak-first-and-then-say-message`: The assistant dials the destination, waits for the operator to speak, delivers the `message` to the destination party, and then connects the customer.\n- `warm-transfer-wait-for-operator-to-speak-first-and-then-say-summary`: The assistant dials the destination, waits for the operator to speak, provides a summary of the call to the destination party, and then connects the customer.\n\n@default 'blind-transfer'",
             "enum": [
               "blind-transfer",
-              "blind-transfer-add-summary-to-sip-header",
               "warm-transfer-say-message",
               "warm-transfer-say-summary",
               "warm-transfer-wait-for-operator-to-speak-first-and-then-say-message",
@@ -4312,10 +4311,6 @@
               }
             ]
           },
-          "sipHeaders": {
-            "type": "object",
-            "description": "These are custom headers to be added to SIP refer during transfer call."
-          },
           "description": {
             "type": "string",
             "description": "This is the description of the destination, used by the AI to choose when and how to transfer the call."