packages: allow discord-ptb-unwrapped and fastflowlm as unfree

With the updated inputs both are checked by the unfree predicate and
evaluation stops on them: discord-ptb now pulls in a separate
-unwrapped package, and nix-amd-ai marked its FastFlowLM NPU runtime
unfree in 2026-10.

Assisted-by: Claude:opus-5-5

modules/packages.nix

@@ -7,6 +7,7 @@
     "castlabs-electron"
     "tidal-hifi"
     "discord-ptb"
+    "discord-ptb-unwrapped"
     "steam"
     "steam-original"
     "steam-unwrapped"
@@ -15,6 +16,7 @@
     "packer"
     "obsidian"
     "hyperplay-ext"
+    "fastflowlm"   # nix-amd-ai NPU runtime, marked unfree since 2026-10
   ];
 
   # List packages installed in system profile.