refactor: centralize agent skills at ~/.agents/skills

modules/home-manager/coding/agents/pi.nix

@@ -15,7 +15,10 @@ in
 
       mcpServers = mkOption {
         type = types.attrsOf types.anything;
-        default = if mcpCfg != null then mcpCfg.servers else {};
+        default =
+          if mcpCfg != null
+          then mcpCfg.servers
+          else {};
         defaultText = literalExpression "config.programs.mcp.servers";
         description = ''
           MCP server configurations for Pi (pi-mcp-adapter).
@@ -41,8 +44,6 @@ in
         '';
       };
 
-      externalSkills = shared.externalSkillsOption;
-
       settings = mkOption {
         type = types.submodule {
           freeformType = types.attrsOf types.anything;
@@ -156,8 +157,11 @@ in
             then let
               filtered = filterNulls v;
             in
-              if filtered == {} then null else filtered
-            else v) attrs
+              if filtered == {}
+              then null
+              else filtered
+            else v)
+          attrs
         );
 
       piSettings = filterNulls cfg.settings;
@@ -177,17 +181,16 @@ in
       # Dynamic home.file entries for agent .md files
       agentFiles =
         if cfg.agentsInput != null
-        then
-          let
-            agentNames = builtins.attrNames cfg.agentsInput.lib.loadAgents;
-          in
-            builtins.listToAttrs (
-              map (name: {
-                name = ".pi/agent/agents/${name}.md";
-                value = {source = "${rendered}/agents/${name}.md";};
-              })
-              agentNames
-            )
+        then let
+          agentNames = builtins.attrNames cfg.agentsInput.lib.loadAgents;
+        in
+          builtins.listToAttrs (
+            map (name: {
+              name = ".pi/agent/agents/${name}.md";
+              value = {source = "${rendered}/agents/${name}.md";};
+            })
+            agentNames
+          )
         else {};
     in {
       home.file = mkMerge [
@@ -213,15 +216,6 @@ in
 
         # ── Agents — pi-subagents .md files ────────────────────────────
         agentFiles
-
-        # ── Skills symlinked from AGENTS repo + external skills ────────
-        (mkIf (cfg.agentsInput != null) {
-          ".pi/agent/skills".source = cfg.agentsInput.lib.mkOpencodeSkills {
-            inherit pkgs;
-            customSkills = "${cfg.agentsInput}/skills";
-            externalSkills = shared.mapExternalSkills cfg.externalSkills;
-          };
-        })
       ];
     });
   }