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/script.rs

@@ -0,0 +1,65 @@
+//! Workflow script — parse and execute user-defined workflow scripts.
+
+use anyhow::Result;
+use tracing::info;
+
+/// A single phase in a parsed workflow script.
+#[derive(Debug, Clone)]
+pub struct WorkflowPhase {
+    pub name: String,
+    pub directive: String,
+}
+
+/// A parsed workflow script with named phases.
+#[derive(Debug, Clone)]
+pub struct WorkflowScript {
+    pub name: String,
+    pub phases: Vec<WorkflowPhase>,
+}
+
+impl WorkflowScript {
+    /// Parse a YAML string into a WorkflowScript.
+    ///
+    /// Expected format:
+    /// ```yaml
+    /// name: my-workflow
+    /// phases:
+    ///   - name: research
+    ///     directive: "Explore the codebase..."
+    ///   - name: implement
+    ///     directive: "Implement the changes..."
+    /// ```
+    pub fn parse(yaml: &str) -> Result<Self> {
+        let parsed: serde_json::Value = serde_yaml_ng::from_str(yaml)
+            .map_err(|e| anyhow::anyhow!("Failed to parse workflow YAML: {e}"))?;
+
+        let name = parsed
+            .get("name")
+            .and_then(|v| v.as_str())
+            .unwrap_or("unnamed")
+            .to_string();
+
+        let mut phases = Vec::new();
+        if let Some(phases_arr) = parsed.get("phases").and_then(|v| v.as_array()) {
+            for phase_val in phases_arr {
+                let phase_name = phase_val
+                    .get("name")
+                    .and_then(|v| v.as_str())
+                    .unwrap_or("phase")
+                    .to_string();
+                let directive = phase_val
+                    .get("directive")
+                    .and_then(|v| v.as_str())
+                    .unwrap_or("")
+                    .to_string();
+                phases.push(WorkflowPhase {
+                    name: phase_name,
+                    directive,
+                });
+            }
+        }
+
+        info!("Parsed workflow script: {name} ({} phases)", phases.len());
+        Ok(WorkflowScript { name, phases })
+    }
+}