Disable pacman CheckSpace to fix read-only mount errors on amd64

NoExtract stops pacman writing /etc/resolv.conf and /etc/hosts, but
pacman's disk-space pre-flight still inspects those bind-mounted
partitions and fails when it sees them as read-only. Commenting out
CheckSpace skips the space check entirely, which is safe in Docker
overlay filesystems.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: corbinlc

Dockerfile.arch

@@ -7,7 +7,8 @@ FROM menci/archlinuxarm:latest AS builder
 # --overwrite '*' handles file conflicts from package splits (e.g. gcc-libs → libgcc+libstdc++).
 RUN sed -i 's/^#DisableSandbox/DisableSandbox/' /etc/pacman.conf && \
     sed -i '/^SigLevel[[:space:]]/c\SigLevel = Never' /etc/pacman.conf && \
-    sed -i '/^DisableSandbox/a NoExtract = etc/resolv.conf etc/hosts' /etc/pacman.conf
+    sed -i '/^DisableSandbox/a NoExtract = etc/resolv.conf etc/hosts' /etc/pacman.conf && \
+    sed -i 's/^CheckSpace/#CheckSpace/' /etc/pacman.conf
 
 RUN pacman -Syu --noconfirm --overwrite '*'
 
@@ -25,7 +26,8 @@ FROM menci/archlinuxarm:latest
 
 RUN sed -i 's/^#DisableSandbox/DisableSandbox/' /etc/pacman.conf && \
     sed -i '/^SigLevel[[:space:]]/c\SigLevel = Never' /etc/pacman.conf && \
-    sed -i '/^DisableSandbox/a NoExtract = etc/resolv.conf etc/hosts' /etc/pacman.conf
+    sed -i '/^DisableSandbox/a NoExtract = etc/resolv.conf etc/hosts' /etc/pacman.conf && \
+    sed -i 's/^CheckSpace/#CheckSpace/' /etc/pacman.conf
 
 RUN pacman -Syu --noconfirm --overwrite '*'