setup usage_rules

mix.exs

@@ -12,7 +12,8 @@ defmodule Mixer.MixProject do
       deps: deps(),
       compilers: [:phoenix_live_view] ++ Mix.compilers(),
       listeners: [Phoenix.CodeReloader],
-      consolidate_protocols: Mix.env() != :dev
+      consolidate_protocols: Mix.env() != :dev,
+      usage_rules: usage_rules()
     ]
   end
 
@@ -114,4 +115,29 @@ defmodule Mixer.MixProject do
       precommit: ["compile --warnings-as-errors", "deps.unlock --unused", "format", "test"]
     ]
   end
+
+  defp usage_rules do
+    [
+      file: "CLAUDE.md",
+      # rules to include directly in CLAUDE.md
+      usage_rules: ["usage_rules:all"],
+      skills: [
+        location: ".claude/skills",
+        # build skills that combine multiple usage rules
+        build: [
+          "ash-framework": [
+            # The description tells people how to use this skill.
+            description: "Use this skill working with Ash Framework or any of its extensions. Always consult this when making any domain changes, features or fixes.",
+            # Include all Ash dependencies
+            usage_rules: [:ash, ~r/^ash_/]
+          ],
+          "phoenix-framework": [
+            description: "Use this skill working with Phoenix Framework. Consult this when working with the web layer, controllers, views, liveviews etc.",
+            # Include all Phoenix dependencies
+            usage_rules: [:phoenix, ~r/^phoenix_/]
+          ]
+        ]
+      ]
+    ]
+  end
 end