ci: switch amiga-gcc image from Docker Hub to GHCR

.claude/skills/copperline-testing/SKILL.md

@@ -242,8 +242,8 @@ toolchain, no build deps, and it bundles AROS):
   retry fresh (a new session usually clears it) rather than waiting it out or
   concluding the source directory is corrupted; `du -sh` on it should read
   a few tens of MB, not more.
-- m68k cross-build: `make m68k-docker` (the `stefanreinauer/amiga-gcc` container;
-  no local toolchain needed).
+- m68k cross-build: `make m68k-docker` (the `ghcr.io/reinauer/container-amiga-gcc`
+  container; no local toolchain needed).
 - `/opt/amiga/bin/m68k-amigaos-gdb` also exists locally — **use this one, not
   the Docker container's gdb**, for the GDB workflow above: it's what worked
   in the confirmed recipe, and running gdb inside the container was the

.github/workflows/ci.yml

@@ -93,7 +93,7 @@ jobs:
     runs-on: ubuntu-latest
     needs: changes
     if: needs.changes.outputs.build == 'true'
-    container: stefanreinauer/amiga-gcc:latest
+    container: ghcr.io/reinauer/container-amiga-gcc:latest
     steps:
       - uses: actions/checkout@v7
       - name: Cross-build CLI for 68000

Makefile

@@ -33,7 +33,7 @@ endif
 
 # Containerised cross-build: same image as CI, so local m68k builds match.
 DOCKER          ?= docker
-AMIGA_GCC_IMAGE ?= stefanreinauer/amiga-gcc:latest
+AMIGA_GCC_IMAGE ?= ghcr.io/reinauer/container-amiga-gcc:latest
 # Run as the calling user, not root: the container bind-mounts $(CURDIR), and
 # without this, files it creates (build/, the m68k binaries) come out root-
 # owned on Linux hosts - breaking any later non-Docker step (e.g. `make dist`)