Update call metadata using partial merge with dot notation paths.

How it works:

• Accepts flat paths with dot notation: { "call.duration": 45, "tags": ["important"] }
• Merges with existing metadata (doesn't replace everything)
• Arrays are replaced, not merged
• Objects are deeply merged

Examples:

Existing metadata:

{
  "call": { "duration": 30, "status": "completed" },
  "insight": { "score": 8 }
}

Update request:

{
  "metadata": {
    "call.duration": 45,
    "tags": ["important", "follow-up"],
    "insight.property_value": 1500000
  }
}

Result:

{
  "call": { "duration": 45, "status": "completed" },
  "insight": { "score": 8, "property_value": 1500000 },
  "tags": ["important", "follow-up"]
}

Notes:

• Path must be alphanumeric with dots (e.g., "call.duration", "insight.value")
• Multi-tenancy is enforced (can only update calls in your org)