[codex-analytics] feature plumbing and emittance (#16640)

---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/16640).
* #16870
* #16706
* #16641
* __->__ #16640

codex-rs/core/src/codex.rs

@@ -55,6 +55,7 @@ use codex_analytics::CompactionPhase;
 use codex_analytics::CompactionReason;
 use codex_analytics::InvocationType;
 use codex_analytics::SubAgentThreadStartedInput;
+use codex_analytics::TurnResolvedConfigFact;
 use codex_analytics::build_track_events_context;
 use codex_app_server_protocol::AuthMode;
 use codex_app_server_protocol::McpServerElicitationRequest;
@@ -190,6 +191,7 @@ use crate::config::resolve_web_search_mode_for_turn;
 use crate::context_manager::ContextManager;
 use crate::context_manager::TotalTokenUsageBreakdown;
 use crate::environment_context::EnvironmentContext;
+use crate::thread_rollout_truncation::initial_history_has_prior_user_turns;
 use codex_config::CONFIG_TOML_FILE;
 use codex_config::types::McpServerConfig;
 use codex_config::types::ShellEnvironmentPolicy;
@@ -2370,6 +2372,11 @@ impl Session {
                 SessionSource::SubAgent(_)
             )
         };
+        let has_prior_user_turns = initial_history_has_prior_user_turns(&conversation_history);
+        {
+            let mut state = self.state.lock().await;
+            state.set_next_turn_is_first(!has_prior_user_turns);
+        }
         match conversation_history {
             InitialHistory::New | InitialHistory::Cleared => {
                 // Defer initial context insertion until the first real turn starts so
@@ -6328,6 +6335,8 @@ pub(crate) async fn run_turn(
             .await;
     }
 
+    track_turn_resolved_config_analytics(&sess, &turn_context, &input).await;
+
     let skills_outcome = Some(turn_context.turn_skills.outcome.as_ref());
     sess.maybe_start_ghost_snapshot(Arc::clone(&turn_context), cancellation_token.child_token())
         .await;
@@ -6631,6 +6640,52 @@ pub(crate) async fn run_turn(
     last_agent_message
 }
 
+async fn track_turn_resolved_config_analytics(
+    sess: &Session,
+    turn_context: &TurnContext,
+    input: &[UserInput],
+) {
+    if !sess.enabled(Feature::GeneralAnalytics) {
+        return;
+    }
+
+    let thread_config = {
+        let state = sess.state.lock().await;
+        state.session_configuration.thread_config_snapshot()
+    };
+    let is_first_turn = {
+        let mut state = sess.state.lock().await;
+        state.take_next_turn_is_first()
+    };
+    sess.services
+        .analytics_events_client
+        .track_turn_resolved_config(TurnResolvedConfigFact {
+            turn_id: turn_context.sub_id.clone(),
+            thread_id: sess.conversation_id.to_string(),
+            num_input_images: input
+                .iter()
+                .filter(|item| {
+                    matches!(item, UserInput::Image { .. } | UserInput::LocalImage { .. })
+                })
+                .count(),
+            submission_type: None,
+            ephemeral: thread_config.ephemeral,
+            session_source: thread_config.session_source,
+            model: turn_context.model_info.slug.clone(),
+            model_provider: turn_context.config.model_provider_id.clone(),
+            sandbox_policy: turn_context.sandbox_policy.get().clone(),
+            reasoning_effort: turn_context.reasoning_effort,
+            reasoning_summary: Some(turn_context.reasoning_summary),
+            service_tier: turn_context.config.service_tier,
+            approval_policy: turn_context.approval_policy.value(),
+            approvals_reviewer: turn_context.config.approvals_reviewer,
+            sandbox_network_access: turn_context.network_sandbox_policy.is_enabled(),
+            collaboration_mode: turn_context.collaboration_mode.mode,
+            personality: turn_context.personality,
+            is_first_turn,
+        });
+}
+
 async fn run_pre_sampling_compact(
     sess: &Arc<Session>,
     turn_context: &Arc<TurnContext>,