Replace PATH injection with post-install executable.path auto-config

Drops the cross-platform PATH-injection workaround in favor of probing
claude availability after install and writing the known install location
to claudeCodeChat.executable.path when it's not on PATH. Terminals for
login/model/usage/slash commands now launch claude directly via
createTerminal's shellPath/shellArgs so they work identically across
PowerShell, cmd, bash, and zsh. WSL nodePath is now optional (recent
Claude ships as a native binary) and its field moved below claudePath.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package.json

@@ -2,7 +2,7 @@
   "name": "claude-code-chat",
   "displayName": "Chat for Claude Code",
   "description": "Beautiful Claude Code Chat Interface for VS Code",
-  "version": "2.0.5",
+  "version": "2.0.6",
   "publisher": "AndrePimenta",
   "author": "Andre Pimenta",
   "repository": {
@@ -162,8 +162,8 @@
         },
         "claudeCodeChat.wsl.nodePath": {
           "type": "string",
-          "default": "/usr/bin/node",
-          "description": "Path to Node.js in the WSL distribution"
+          "default": "",
+          "description": "Optional path to Node.js in the WSL distribution. Only needed if Claude was installed via npm. Recent Claude installs ship as a native executable and don't require Node."
         },
         "claudeCodeChat.wsl.claudePath": {
           "type": "string",