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

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[//]: # (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/app-server/src/main.rs

@@ -12,6 +12,7 @@ use std::path::PathBuf;
 // Debug-only test hook: lets integration tests point the server at a temporary
 // managed config file without writing to /etc.
 const MANAGED_CONFIG_PATH_ENV_VAR: &str = "CODEX_APP_SERVER_MANAGED_CONFIG_PATH";
+const DISABLE_MANAGED_CONFIG_ENV_VAR: &str = "CODEX_APP_SERVER_DISABLE_MANAGED_CONFIG";
 
 #[derive(Debug, Parser)]
 struct AppServerArgs {
@@ -40,10 +41,13 @@ struct AppServerArgs {
 fn main() -> anyhow::Result<()> {
     arg0_dispatch_or_else(|arg0_paths: Arg0DispatchPaths| async move {
         let args = AppServerArgs::parse();
-        let managed_config_path = managed_config_path_from_debug_env();
-        let loader_overrides = LoaderOverrides {
-            managed_config_path,
-            ..Default::default()
+        let loader_overrides = if disable_managed_config_from_debug_env() {
+            LoaderOverrides::without_managed_config_for_tests()
+        } else {
+            LoaderOverrides {
+                managed_config_path: managed_config_path_from_debug_env(),
+                ..Default::default()
+            }
         };
         let transport = args.listen;
         let session_source = args.session_source;
@@ -63,6 +67,17 @@ fn main() -> anyhow::Result<()> {
     })
 }
 
+fn disable_managed_config_from_debug_env() -> bool {
+    #[cfg(debug_assertions)]
+    {
+        if let Ok(value) = std::env::var(DISABLE_MANAGED_CONFIG_ENV_VAR) {
+            return matches!(value.as_str(), "1" | "true" | "TRUE" | "yes" | "YES");
+        }
+    }
+
+    false
+}
+
 fn managed_config_path_from_debug_env() -> Option<PathBuf> {
     #[cfg(debug_assertions)]
     {