Stage and apply event-field overrides at tool lifecycle boundaries

Stage writable event-field overrides by tool call id so they can be applied at the correct point in the turn lifecycle. Capture input overrides from tool_call_complete, capture output overrides from tool_result, and clear staged overrides defensively at turn start and shutdown.

Also honor user_message text overrides when starting a turn, add the helper that applies staged overrides to the agent at dispatch boundaries, and cover the behavior with tests for staged input/output overrides.

1 files changed, 10 insertions, 4 deletions

diff --git a/src/extension_loader.zig b/src/extension_loader.zig
index 4620a2e..1c29ceb 100644
--- a/src/extension_loader.zig
+++ b/src/extension_loader.zig
@@ -220,7 +220,11 @@ pub fn loadFromDirs(
     for (found.items) |f| {
         var entries: std.array_list.Managed(Entry) = .init(allocator);
         defer entries.deinit();
-        try runtime.evalEntries(f.script_path, f.package_root, &entries);
+        runtime.evalEntries(f.script_path, f.package_root, &entries) catch |err| {
+            // Entries collected before the failure hold Lua refs + names.
+            for (entries.items) |e| runtime.dropEntry(e);
+            return err;
+        };
         for (entries.items) |e| {
             try cands.append(.{ .entry = e, .source = f.source, .script_path = f.script_path });
         }
@@ -254,10 +258,13 @@ pub fn loadFromDirs(
             runtime.dropEntry(cnd.entry);
             continue;
         }
+        // Log before activating: `activateEntry` consumes the entry
+        // (frees its name), so `cnd.entry.name` is dangling afterwards.
+        std.log.debug("extension: activating '{s}' ({s})", .{ cnd.entry.name, cnd.source.label() });
         runtime.activateEntry(cnd.entry) catch |err| {
             logConflict(
-                "extension '{s}' ({s}: {s}) failed to activate: {t}",
-                .{ cnd.entry.name, cnd.source.label(), cnd.script_path, err },
+                "extension ({s}: {s}) failed to activate: {t}",
+                .{ cnd.source.label(), cnd.script_path, err },
             );
             // activateEntry consumed the entry already. Drop the rest.
             var j = i + 1;
@@ -265,7 +272,6 @@ pub fn loadFromDirs(
             cands.clearRetainingCapacity();
             return err;
         };
-        std.log.debug("extension: activated '{s}' ({s})", .{ cnd.entry.name, cnd.source.label() });
     }
     cands.clearRetainingCapacity();