feat(TASK-033): add hook config schema across all scopes

Introduce src/hooks.rs as a types-only module (HookDef, HooksMap) and
plumb hooks:/global_hooks: config fields through every scope:

- Config + AppConfig hooks field, both Default impls, the manual
  from_config copy, and a COYOTE_HOOKS env override
- Role frontmatter: hand-parsed hooks arm, private field, getter, and
  JSON-inline re-serialization in Role::export (malformed maps degrade
  to None)
- AgentConfig + Graph: hooks + global_hooks on both structs, copied in
  AgentConfig::from_graph, with a per-agent global_hooks env override
- paths::hooks_dir() = <config_dir>/hooks with COYOTE_HOOKS_DIR override
- Commented hooks: block in the global config template (global scope
  only; no global_hooks key)

No engine or dispatch logic yet; existing configs parse unchanged.

src/graph/executor.rs

@@ -928,6 +928,8 @@ mod tests {
             max_concurrent_agents: None,
             max_agent_depth: None,
             global_tools: Vec::new(),
+            hooks: Default::default(),
+            global_hooks: Vec::new(),
             mcp_servers: Vec::new(),
             mcp_tools: None,
             skills_enabled: None,

src/graph/map.rs

@@ -497,6 +497,8 @@ mod tests {
             max_concurrent_agents: None,
             max_agent_depth: None,
             global_tools: Vec::new(),
+            hooks: Default::default(),
+            global_hooks: Vec::new(),
             mcp_servers: Vec::new(),
             mcp_tools: None,
             skills_enabled: None,

src/graph/types.rs

@@ -1,4 +1,5 @@
 use crate::config::AgentVariable;
+use crate::hooks::HooksMap;
 use anyhow::Result;
 use indexmap::IndexMap;
 use serde::{Deserialize, Serialize};
@@ -43,6 +44,12 @@ pub struct Graph {
     #[serde(default)]
     pub global_tools: Vec<String>,
 
+    #[serde(default)]
+    pub hooks: HooksMap,
+
+    #[serde(default)]
+    pub global_hooks: Vec<String>,
+
     #[serde(default)]
     pub mcp_servers: Vec<String>,
 
@@ -611,6 +618,52 @@ nodes:
         }
     }
 
+    #[test]
+    fn graph_hooks_and_global_hooks_parse_and_round_trip() {
+        let yaml = r#"
+name: g
+start: e
+hooks:
+  tool.started:
+    - name: notify
+      command: ./hooks/notify.sh
+global_hooks:
+  - tool.started.notify
+nodes:
+  e:
+    id: e
+    type: end
+    output: done
+"#;
+        let graph: Graph = serde_yaml::from_str(yaml).unwrap();
+
+        assert_eq!(graph.hooks["tool.started"][0].name, "notify");
+        assert_eq!(graph.hooks["tool.started"][0].command, "./hooks/notify.sh");
+        assert_eq!(graph.global_hooks, vec!["tool.started.notify"]);
+
+        let reparsed: Graph =
+            serde_yaml::from_str(&serde_yaml::to_string(&graph).unwrap()).unwrap();
+        assert_eq!(reparsed.hooks, graph.hooks);
+        assert_eq!(reparsed.global_hooks, graph.global_hooks);
+    }
+
+    #[test]
+    fn graph_without_hooks_keys_parses_empty() {
+        let yaml = r#"
+name: g
+start: e
+nodes:
+  e:
+    id: e
+    type: end
+    output: done
+"#;
+        let graph: Graph = serde_yaml::from_str(yaml).unwrap();
+
+        assert!(graph.hooks.is_empty());
+        assert!(graph.global_hooks.is_empty());
+    }
+
     #[test]
     fn agent_node_teammates_parses_and_defaults_false() {
         let yaml = r#"

src/graph/validator.rs

@@ -1459,6 +1459,8 @@ mod tests {
             max_concurrent_agents: None,
             max_agent_depth: None,
             global_tools: Vec::new(),
+            hooks: Default::default(),
+            global_hooks: Vec::new(),
             mcp_servers: Vec::new(),
             mcp_tools: None,
             skills_enabled: None,