feat: support web calls in webhook

[cubic-dev-local]

## What does this PR do?

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• N/A I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. If N/A, write N/A here and check the checkbox.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

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Based on: calcom/cal.com#23788

---

Summary by cubic

Add web call support to the Retell webhook. For web calls (no phone numbers), we resolve the agent and charge credits to the correct user/team.

• New Features

  • Handle web_call events by looking up the agent via providerAgentId and charging credits to the associated user or team.
  • Keep skipping inbound phone calls; web calls bypass the direction check.
  • Added unit tests for web calls (agent and team cases, missing data paths).

• Refactors

  • Extracted credit charging into a helper with a per-minute rate (defaults to $0.29) and rounded-up credits.
  • Made phone fields optional in the schema and improved logging/errors.

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (all 1 issues)

Understand the root cause of the following 1 issues and fix them.


<file name="apps/web/app/api/webhooks/retell-ai/route.ts">

<violation number="1" location="apps/web/app/api/webhooks/retell-ai/route.ts:122">
The webhook returns a `200 OK` success response even when credit charging fails for critical reasons, such as the agent or phone number not being found. This can lead to silent, unbilled calls and revenue loss, as the failure is only recorded in logs and not propagated as an error state.</violation>
</file>

_{React with 👍 or 👎 to teach cubic. Mention @cubic-dev-ai to give feedback, ask questions, or re-run the review.}

[cubic-dev-ai]

The webhook returns a 200 OK success response even when credit charging fails for critical reasons, such as the agent or phone number not being found. This can lead to silent, unbilled calls and revenue loss, as the failure is only recorded in logs and not propagated as an error state.

Prompt for AI agents

Address the following comment on apps/web/app/api/webhooks/retell-ai/route.ts at line 122:

<comment>The webhook returns a `200 OK` success response even when credit charging fails for critical reasons, such as the agent or phone number not being found. This can lead to silent, unbilled calls and revenue loss, as the failure is only recorded in logs and not propagated as an error state.</comment>

<file context>
@@ -124,15 +117,74 @@ async function handleCallAnalyzed(callData: any) {
   }
+}
+
+async function handleCallAnalyzed(callData: any) {
+  const { from_number, call_id, call_cost, call_type, agent_id } = callData;
 
</file context>

[internal] Confidence score: 10/10

[internal] Posted by: System Design Agent

[github-actions]

This PR is being marked as stale due to inactivity.