feat(home): add pi coding agent configuration

- Add pi module for terminal configuration
- Include pi-coding-agent package in home.packages
- Configure pi with llama-swap provider via models.json
- Enable pi for mac-va-mbp-work profile

modules/home/programs/terminal/pi/lib.nix

@@ -0,0 +1,60 @@
+{ lib }:
+let
+  inherit (lib)
+    mapAttrs
+    filterAttrs
+    any
+    flatten
+    listToAttrs
+    nameValuePair
+    ;
+in
+{
+  toPiModels =
+    llamaSwapConfig:
+    let
+      textGenModels = filterAttrs
+        (
+          name: model: any (t: t == "text-generation") (model.metadata.type or [ ])
+        )
+        (llamaSwapConfig.models or { });
+
+      localModels = mapAttrs
+        (
+          name: model:
+            {
+              id = name;
+              inherit (model) name;
+            }
+            // (
+              if model.macros.ctx or null != null then
+                {
+                  contextWindow = lib.toInt model.macros.ctx;
+                }
+              else
+                { }
+            )
+        )
+        textGenModels;
+
+      peerModels = listToAttrs (
+        flatten (
+          map
+            (
+              peer:
+              map
+                (
+                  modelName:
+                  nameValuePair modelName {
+                    id = modelName;
+                    name = modelName;
+                  }
+                )
+                peer.models
+            )
+            (builtins.attrValues (llamaSwapConfig.peers or { }))
+        )
+      );
+    in
+    builtins.attrValues (localModels // peerModels);
+}