feat: initial agent graph scaffolding

src/graph/mod.rs

@@ -0,0 +1,19 @@
+//! Graph-based agent orchestration. Declarative YAML workflows over a shared
+//! JSON state, composed of agent/script/approval/input/end nodes.
+
+pub mod parser;
+pub mod types;
+
+pub use parser::{GraphParser, agent_has_graph, load_agent_graph};
+pub use types::{
+    AgentNode, ApprovalNode, EndNode, Graph, GraphSettings, GraphState, InputNode, Node, NodeType,
+    ScriptNode,
+};
+
+pub const GRAPH_SCHEMA_VERSION: &str = "1.0";
+
+pub const DEFAULT_MAX_LOOP_ITERATIONS: usize = 100;
+
+/// Serialized-state size above which scripts receive state via a temp file
+/// instead of an env var.
+pub const MAX_STATE_SIZE_BYTES: usize = 32 * 1024;