fix: delete management/ncp.ps1 - it shadowed the ncp.cmd PATH shim

PowerShell resolves ExternalScript (.ps1) ahead of Application (.cmd), and both
lived in the directory the installer puts on PATH -- so in PowerShell `ncp` ran
the .ps1 and was execution-policy-bound again, the exact thing the .cmd exists
to avoid. Its other justification (giving ncp to pwsh on Linux) stopped being
true once /usr/local/bin/ncp existed: pwsh runs a PATH symlink to a shell script
as an Application. A test now prevents the file coming back.

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

bin/restore-linux.sh

@@ -82,20 +82,6 @@ EOF
         echo "Registered promethean in ~/.bashrc."
     fi
 
-    # Same ncp inside PowerShell, if pwsh is installed here. bash functions are
-    # invisible to pwsh, so without this `ncp` is "not recognized" there even
-    # though it works in bash. install-windows.ps1 does this on the Windows side;
-    # this profile lives outside the repo, so a restore has to re-add it.
-    if command -v pwsh >/dev/null; then
-        ps_profile="$HOME/.config/powershell/profile.ps1"
-        if ! grep -q "NexusOS ncp" "$ps_profile" 2>/dev/null; then
-            mkdir -p "$(dirname "$ps_profile")"
-            printf '\n# NexusOS ncp\nfunction ncp { & "%s/management/ncp.ps1" @args }\n' \
-                "$NEXUS_ROOT" >> "$ps_profile"
-            echo "Registered ncp in $ps_profile."
-        fi
-    fi
-
     # The AMD box runs CPU-only (Vega 20, 4GB VRAM thrashes). An NVIDIA box should not.
     if command -v nvidia-smi >/dev/null && command -v sqlite3 >/dev/null && \
        [ "$(sqlite3 "$NEXUS_ROOT/synapse/memory/memory.db" \