feat(grid-agent): add chat and IM interactions (#123)

crates/metacrate-grid-agent/src/policy.rs

@@ -831,6 +831,27 @@ impl PolicyGateway {
 
     #[must_use]
     pub fn tools_for(&self, context: &PolicyRequestContext, now: u64) -> Vec<ToolDefinition> {
+        self.tools_for_capabilities(context, now, None)
+    }
+
+    /// Returns only origin-allowed tools whose capability is in `capabilities`.
+    /// An empty set exposes no tools; filtering can never broaden policy access.
+    #[must_use]
+    pub fn tools_for_capability_set(
+        &self,
+        context: &PolicyRequestContext,
+        now: u64,
+        capabilities: &BTreeSet<Capability>,
+    ) -> Vec<ToolDefinition> {
+        self.tools_for_capabilities(context, now, Some(capabilities))
+    }
+
+    fn tools_for_capabilities(
+        &self,
+        context: &PolicyRequestContext,
+        now: u64,
+        capabilities: Option<&BTreeSet<Capability>>,
+    ) -> Vec<ToolDefinition> {
         if let OriginKind::InternalScheduler(id) = &context.origin.0 {
             let state = lock(&self.state);
             let Some(grant) = state.scheduler_grants.get(id) else {
@@ -845,7 +866,10 @@ impl PolicyGateway {
             return self
                 .tools
                 .get(&grant.tool)
-                .filter(|tool| origin_allows(tool, OriginClass::InternalScheduler))
+                .filter(|tool| {
+                    origin_allows(tool, OriginClass::InternalScheduler)
+                        && capabilities.is_none_or(|allowed| allowed.contains(&tool.capability))
+                })
                 .map(|tool| vec![tool.definition.clone()])
                 .unwrap_or_default();
         }
@@ -854,7 +878,10 @@ impl PolicyGateway {
         };
         self.tools
             .values()
-            .filter(|tool| origin_allows(tool, classified.origin))
+            .filter(|tool| {
+                origin_allows(tool, classified.origin)
+                    && capabilities.is_none_or(|allowed| allowed.contains(&tool.capability))
+            })
             .map(|tool| tool.definition.clone())
             .collect()
     }