refactor: use home.sessionPath instead of hardcoded PATH

- Replace hardcoded PATH with home.sessionPath for proper ordering
- Use ${config.home.homeDirectory} and ${config.home.username} for portability
- Add PNPM_HOME for pnpm global packages
- Remove hardcoded node version path (install pi via pnpm i -g)

home/default.nix

@@ -1,4 +1,4 @@
-{ pkgs, lib, ... }:
+{ config, pkgs, lib, ... }:
 {
   imports = [
     ./cli.nix
@@ -12,11 +12,43 @@
 
   home.stateVersion = "24.11";
 
+  # PATH через sessionPath — nix сам собирает в правильном порядке
+  home.sessionPath = [
+    # macOS Homebrew (ARM и Intel)
+    "/opt/homebrew/bin"
+    "/usr/local/bin"
+    
+    # System
+    "/usr/bin"
+    "/bin"
+    "/sbin"
+    "/usr/sbin"
+    
+    # Nix (darwin-rebuild, nix и т.д.)
+    "/run/current-system/sw/bin"
+    "/nix/var/nix/profiles/default/bin"
+    
+    # User nix profile
+    "${config.home.homeDirectory}/.nix-profile/bin"
+    "/etc/profiles/per-user/${config.home.username}/bin"
+    
+    # User binaries
+    "${config.home.homeDirectory}/bin"
+    "${config.home.homeDirectory}/.local/bin"
+    
+    # npm/pnpm global — установи pi через: pnpm i -g @mariozechner/pi-coding-agent
+    "${config.home.homeDirectory}/.npm-global/bin"
+    "${config.home.homeDirectory}/.local/share/pnpm"
+    
+    # opencode (если установлен)
+    "${config.home.homeDirectory}/.opencode/bin"
+  ];
+
   home.sessionVariables = {
     SEARXNG_URL = "https://search.iscg.dev";
-    # NOTE: include /run/current-system/sw/bin for darwin-rebuild, /nix/var/nix/profiles/default/bin for nix
-    PATH = "/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:/sbin:/usr/sbin:/run/current-system/sw/bin:/nix/var/nix/profiles/default/bin:/etc/profiles/per-user/mikl/bin:$HOME/.nix-profile/bin:$HOME/bin:$HOME/.local/bin:$HOME/.npm-global/bin:/Users/mikl/.opencode/bin:/Users/mikl/.local/share/pi-node/node-v22.23.1-darwin-arm64/bin";
     EDITOR = "micro";
     VISUAL = "micro";
+    # PNPM_HOME для глобальных пакетов
+    PNPM_HOME = "${config.home.homeDirectory}/.local/share/pnpm";
   };
 }