feat: put ncp on PATH on both platforms; rename WSL reqs to Windows

Ports the ncp PATH work from upstream. Registering ncp as a shell-profile
function failed three ways on Windows: the default Restricted execution policy
blocks the profile itself, profiles don't exist outside PowerShell (cmd, Win+R,
Task Scheduler), and the self-elevating installer writes the admin's profile.

Windows now ships management/ncp.cmd and the installer appends management\ to
the Machine PATH via [Environment]::SetEnvironmentVariable -- never setx, which
truncates PATH at 1024 chars. A .cmd is exempt from the execution policy.

Linux symlinks /usr/local/bin/ncp -> management/nexus-cli.sh, falling back to
the old .bashrc function when sudo is unavailable.

Also renames requirements-wsl.txt to requirements-windows.txt and purges stale
WSL references, including vite.config.js's dev-server comment and
controlpanel.py's "Check WSLg." error string.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

bin/restore-linux.sh

@@ -52,11 +52,20 @@ if [ "$stage" = "runtime" ]; then
         echo "Warning: bin/fetch-ollama.sh not found — skipping Ollama fetch."
     fi
 
-    # Shell wiring: the `ncp` function and the Promethean venv alias. This is the
-    # only place they get registered now that bin/install.sh is gone. Guarded by a
-    # grep so an in-place restore is a no-op and a scratch clone can't re-point an
-    # already-wired ~/.bashrc at itself.
-    if ! grep -q "management/nexus-cli.sh" "$HOME/.bashrc" 2>/dev/null; then
+    # `ncp` on PATH, not a shell function: /usr/local/bin is visible to sh, cron,
+    # systemd units and .desktop Exec lines, none of which read ~/.bashrc. The
+    # Windows installer does the matching thing with management\ncp.cmd on PATH.
+    # Falls back to the old ~/.bashrc function when there's no sudo (a shell
+    # function shadows the symlink anyway, so having both is harmless).
+    ncp_link="/usr/local/bin/ncp"
+    ncp_target="$NEXUS_ROOT/management/nexus-cli.sh"
+    if [ "$(readlink -f "$ncp_link" 2>/dev/null)" = "$ncp_target" ]; then
+        echo "ncp already on PATH at $ncp_link."
+    elif sudo ln -sfn "$ncp_target" "$ncp_link"; then
+        echo "Registered ncp at $ncp_link."
+    elif ! grep -q "management/nexus-cli.sh" "$HOME/.bashrc" 2>/dev/null; then
+        # Guarded by a grep so an in-place restore is a no-op and a scratch clone
+        # can't re-point an already-wired ~/.bashrc at itself.
         cat >> "$HOME/.bashrc" <<EOF
 
 # Nexus
@@ -64,7 +73,7 @@ ncp() {
     $NEXUS_ROOT/management/nexus-cli.sh "\$@"
 }
 EOF
-        echo "Registered ncp in ~/.bashrc."
+        echo "No sudo for $ncp_link — registered ncp in ~/.bashrc instead."
     fi
 
     if ! grep -qF "alias promethean=" "$HOME/.bashrc" 2>/dev/null; then