fix(tauri): replace silent let _ = with structured logging across 20 modules

Replace error-swallowing let _ = patterns with tracing::warn! in browser,
classroom, gateway, intelligence, memory, pipeline, secure_storage, and
viking command handlers. Ensures errors are observable in production logs.

desktop/src-tauri/src/pipeline_commands/crud.rs

@@ -47,6 +47,7 @@ pub struct WorkflowStepInput {
 }
 
 /// Create a new pipeline as a YAML file
+// @connected
 #[tauri::command]
 pub async fn pipeline_create(
     state: State<'_, Arc<PipelineState>>,
@@ -132,6 +133,7 @@ pub async fn pipeline_create(
 }
 
 /// Update an existing pipeline
+// @connected
 #[tauri::command]
 pub async fn pipeline_update(
     state: State<'_, Arc<PipelineState>>,
@@ -201,6 +203,7 @@ pub async fn pipeline_update(
 }
 
 /// Delete a pipeline
+// @connected
 #[tauri::command]
 pub async fn pipeline_delete(
     state: State<'_, Arc<PipelineState>>,