acp: Add telemetry (#36894)

Release Notes:

- N/A

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/agent_servers/src/agent_servers.rs

@@ -36,6 +36,7 @@ pub trait AgentServer: Send {
     fn name(&self) -> SharedString;
     fn empty_state_headline(&self) -> SharedString;
     fn empty_state_message(&self) -> SharedString;
+    fn telemetry_id(&self) -> &'static str;
 
     fn connect(
         &self,

crates/agent_servers/src/claude.rs

@@ -43,6 +43,10 @@ use acp_thread::{AcpThread, AgentConnection, AuthRequired, LoadError, MentionUri
 pub struct ClaudeCode;
 
 impl AgentServer for ClaudeCode {
+    fn telemetry_id(&self) -> &'static str {
+        "claude-code"
+    }
+
     fn name(&self) -> SharedString {
         "Claude Code".into()
     }

crates/agent_servers/src/custom.rs

@@ -22,6 +22,10 @@ impl CustomAgentServer {
 }
 
 impl crate::AgentServer for CustomAgentServer {
+    fn telemetry_id(&self) -> &'static str {
+        "custom"
+    }
+
     fn name(&self) -> SharedString {
         self.name.clone()
     }

crates/agent_servers/src/gemini.rs

@@ -17,6 +17,10 @@ pub struct Gemini;
 const ACP_ARG: &str = "--experimental-acp";
 
 impl AgentServer for Gemini {
+    fn telemetry_id(&self) -> &'static str {
+        "gemini-cli"
+    }
+
     fn name(&self) -> SharedString {
         "Gemini CLI".into()
     }