Remove Warp cloud features and OpenTelemetry

Settings cleanup:
- Remove billing_and_usage, main_page, referrals_page, show_blocks_view,
  environments_page, handoff_environment_creation_modal,
  custom_inference_modal, remove_custom_endpoint_confirmation_dialog,
  transfer_ownership_confirmation_modal, delete_environment_confirmation_dialog
- Remove SettingsSection variants: Account, BillingAndUsage, Referrals,
  SharedBlocks, CloudEnvironments, OzCloudAPIKeys
- Remove SettingsPageViewHandle variants: Main, BillingAndUsage, Referrals,
  CloudEnvironments, OzCloudAPIKeys, SharedBlocks
- Add Platform variant for PlatformPageView
- Gut custom inference endpoint UI from ai_page.rs
- Gut transfer ownership modal from teams_page.rs
- Stub environment_management_pane as dead code
- Remove create_discount_badge usage
- Remove handle_experiment_change call

OpenTelemetry removal:
- Remove opentelemetry, opentelemetry-http, opentelemetry-otlp,
  opentelemetry_sdk, tracing-opentelemetry dependencies
- Replace tracing module with no-op stub
- Delete native.rs and cloud_agent_auth.rs

Bug fixes (prior work):
- Fix apply_diffs() to use markdown_unescaped(ctx)
- Fix notebook executor AIDocumentId handling
- Fix margin/corner-radius consistency in requested_command.rs
- Add document tool handlers to extract_tool_result_content()
- Fix deprecated from_byte_stream in MCP SSE transport
- Fix Cargo.toml profile package spec
- Upgrade rust-toolchain to 1.94.1

app/src/tracing.rs

@@ -1,102 +1,30 @@
-#[cfg(not(target_family = "wasm"))]
-use std::time::Duration;
-
 use tracing::subscriber;
 
-#[cfg(not(target_family = "wasm"))]
-mod cloud_agent_auth;
-#[cfg(not(target_family = "wasm"))]
-mod native;
-
-#[cfg(not(target_family = "wasm"))]
-const DEFAULT_EXPORT_TIMEOUT: Duration = Duration::from_secs(10);
-
 pub fn init() -> anyhow::Result<Initialization> {
-    #[cfg(target_family = "wasm")]
-    {
-        install_no_subscriber()?;
-        Ok(Initialization::default())
-    }
-
-    #[cfg(not(target_family = "wasm"))]
-    native::init()
+    subscriber::set_global_default(subscriber::NoSubscriber::new())?;
+    Ok(Initialization::default())
 }
 
 #[cfg(not(target_family = "wasm"))]
-/// Starts cloud-agent trace credential refresh after authenticated application services exist.
-///
-/// The exporter and dispatch credential are initialized earlier by [`init`]. This later lifecycle
-/// hook supplies the authenticated managed-secrets client needed to mint replacements without
-/// broadening tracing initialization to ordinary application processes.
 pub fn start_auth_refresh(
-    client: std::sync::Arc<dyn warp_managed_secrets::client::ManagedSecretsClient>,
-    ctx: &mut warpui::AppContext,
+    _client: std::sync::Arc<dyn warp_managed_secrets::client::ManagedSecretsClient>,
+    _ctx: &mut warpui::AppContext,
 ) {
-    native::start_auth_refresh(client, ctx);
 }
 
-fn install_no_subscriber() -> anyhow::Result<()> {
-    // Configure the global tracing subscriber to not care about any spans or
-    // events.
-    //
-    // This is done so that we prevent the `tracing` crate from writing out log
-    // lines for spans and trace events.
-    subscriber::set_global_default(subscriber::NoSubscriber::new())?;
-    Ok(())
-}
-
-#[cfg_attr(target_family = "wasm", derive(Default))]
+#[derive(Default)]
 pub struct Initialization {
     initialization_warning: Option<anyhow::Error>,
-    #[cfg(not(target_family = "wasm"))]
-    active_spans: Option<native::ActiveSpanRegistry>,
-    #[cfg(not(target_family = "wasm"))]
-    provider: Option<opentelemetry_sdk::trace::SdkTracerProvider>,
-    #[cfg(not(target_family = "wasm"))]
-    shutdown_timeout: std::time::Duration,
-}
-
-#[cfg(not(target_family = "wasm"))]
-impl Default for Initialization {
-    fn default() -> Self {
-        Self {
-            initialization_warning: None,
-            active_spans: None,
-            provider: None,
-            shutdown_timeout: DEFAULT_EXPORT_TIMEOUT,
-        }
-    }
 }
 
 impl Initialization {
     pub fn log_initialization_warning(&mut self) {
         if let Some(err) = self.initialization_warning.take() {
-            log::warn!("Failed to initialize cloud-agent OpenTelemetry exporting: {err:#}");
+            log::warn!("Tracing initialization warning: {err:#}");
         }
     }
 
-    pub(crate) fn shutdown(&mut self) {
-        #[cfg(not(target_family = "wasm"))]
-        {
-            match (self.active_spans.take(), self.provider.take()) {
-                (Some(active_spans), Some(provider)) => {
-                    if let Err(err) = active_spans.shutdown(&provider, self.shutdown_timeout) {
-                        log::warn!(
-                            "Failed to shut down cloud-agent OpenTelemetry exporting: {err}"
-                        );
-                    }
-                }
-                (None, Some(provider)) => {
-                    if let Err(err) = provider.shutdown_with_timeout(self.shutdown_timeout) {
-                        log::warn!(
-                            "Failed to shut down cloud-agent OpenTelemetry exporting: {err}"
-                        );
-                    }
-                }
-                (Some(_), None) | (None, None) => {}
-            }
-        }
-    }
+    pub(crate) fn shutdown(&mut self) {}
 }
 
 impl Drop for Initialization {