Split journal tools from default definitions, expose to all for now

journal_definitions() separated from definitions() in memory.rs.
All agents get memory + journal tools via memory_and_journal_definitions().
TODO: implement per-agent tool whitelist from header to properly
restrict journal tools to journal agent only.

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/thought/mod.rs

@@ -128,3 +128,11 @@ pub fn all_definitions() -> Vec<ToolDef> {
 pub fn memory_definitions() -> Vec<ToolDef> {
     memory::definitions()
 }
+
+/// Return memory + journal tool definitions.
+/// Used by the journal agent only.
+pub fn memory_and_journal_definitions() -> Vec<ToolDef> {
+    let mut defs = memory::definitions();
+    defs.extend(memory::journal_definitions());
+    defs
+}