feat(tui): add usage overlay and sidebar for displaying usage statistics and tasks

feat(tui): implement status bar with connection and turn state indicators
feat(tui): create workflow panel for agent status and progress visualization
feat(web): introduce web frontend interface with static file serving
feat(ws): add WebSocket interface for real-time communication and session management

apps/infrastructure/src/workflow/engine/execution.rs

@@ -0,0 +1,31 @@
+//! Workflow execution — runs a parsed workflow script phase by phase.
+
+use anyhow::Result;
+use tracing::info;
+
+use crate::llm::provider::LlmClient;
+use crate::tools::ToolCtx;
+use crate::workflow::engine::primitives::execute_primitive;
+use crate::workflow::script::WorkflowScript;
+
+/// Execute each phase of a workflow script sequentially.
+///
+/// Flow: for each phase → execute_primitive → collect result.
+pub async fn execute_workflow(
+    script: &WorkflowScript,
+    tool_ctx: &ToolCtx,
+    _llm_client: &LlmClient,
+) -> Result<Vec<String>> {
+    info!(
+        "Executing workflow: {} ({} phases)",
+        script.name,
+        script.phases.len()
+    );
+    let mut results = Vec::new();
+    for phase in &script.phases {
+        info!("Executing phase: {}", phase.name);
+        let result = execute_primitive(&phase.directive, tool_ctx).await?;
+        results.push(result);
+    }
+    Ok(results)
+}