feat(nushell): add nu_libs autoload package

fix(notgraph): replace sort_by with sort_by_key (clippy)

nushell/.config/nushell/autoload/nu_libs.nu

@@ -0,0 +1,10 @@
+# nu_libs — load all lib/* modules on shell startup
+# Managed by notfiles (nushell package). Link with: notfiles link nushell
+# lib/ai is excluded from lib/mod.nu (requires runtime deps) — loaded separately below.
+# lib/extensions is excluded (requires external project repos) — load manually as needed.
+
+const NU_LIBS     = "/Users/joe/dev/nu_libs/lib/mod.nu"
+const NU_LIBS_AI  = "/Users/joe/dev/nu_libs/lib/ai/mod.nu"
+
+use $NU_LIBS *
+use $NU_LIBS_AI *