fix agent-browser PATH: add npm global bin to zsh path

- Add npm global bin dir to zsh path array so agent-browser
  (and other npm -g binaries) are found in interactive shells
- Fix activation check to look for the binary at the actual npm
  prefix path instead of relying on command -v with wrong PATH

home/agent-browser.nix

@@ -21,7 +21,8 @@ lib.mkIf (!hostConfig.isDarwin) {
       ]
     }:$PATH"
 
-    if ! command -v agent-browser >/dev/null 2>&1; then
+    npm_bin="$(npm prefix -g 2>/dev/null)/bin"
+    if [ ! -x "$npm_bin/agent-browser" ]; then
       npm install -g agent-browser 2>/dev/null || true
     fi
   '';

home/zsh.nix

@@ -83,6 +83,7 @@
           "$BUN_INSTALL/bin"
           "$HOME/.antigravity/antigravity/bin"
           "$HOME/.opencode/bin"
+          "$(npm prefix -g 2>/dev/null)/bin"
           "${pkgs.postgresql_17}/bin"
           "$HOME/.nix-profile/bin"
           "/run/wrappers/bin"