Migrate docker-ce, tailscale to sysexts; remove terra repo

- Remove docker-ce package and repo (now via sysext)
- Remove tailscale package and repo (now via sysext)
- Remove terra repo (was only needed for zed)
- Update SYSEXTS.md with migration progress (~1.76GB saved)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: shanemcd

docs/SYSEXTS.md

@@ -10,6 +10,15 @@ We're on a journey to remove as much as possible from our bootc container image
 |---------|--------|------|------------|-----------|
 | Cursor | `cursor` | community | ~594 MB | [PR #25](https://github.com/fedora-sysexts/community/pull/25) |
 | 1Password GUI | `1password-gui` | community | ~503 MB | Existing (aarch64: [PR #26](https://github.com/fedora-sysexts/community/pull/26)) |
+| libvirt + qemu | `libvirtd-desktop` | fedora | ~500+ MB | Available (F43 not on extensions.fcos.fr yet, use [GitHub releases](https://github.com/fedora-sysexts/fedora/releases/tag/libvirtd-desktop)) |
+| `docker-ce` | `docker-ce` | community | ~98 MB | Available |
+| `tailscale` | `tailscale` | community | ~65 MB | Available |
+
+### Removed from image (no sysext)
+
+| Package | Size | Notes |
+|---------|------|-------|
+| `zed` | ~357 MB | Removed entirely, install via Flatpak or manually if needed |
 
 ### Upstream contributions
 
@@ -29,10 +38,7 @@ These packages have sysext equivalents and could be removed from the Containerfi
 | `ripgrep` | `ripgrep` | fedora | small | |
 | `zsh` | `zsh` | fedora | small | |
 | `tmux` | `tmux` | fedora | small | |
-| `docker-ce` | `docker-ce` | community | ~98 MB | |
-| `tailscale` | `tailscale` | community | ~65 MB | |
 | `1password-cli` | `1password-cli` | community | small | |
-| libvirt + qemu | `libvirtd-desktop` | fedora | ~500+ MB | Large savings potential |
 
 ### Must stay in Containerfile
 
@@ -50,11 +56,9 @@ These cannot be sysexts due to technical limitations:
 
 | Package | Size | Notes |
 |---------|------|-------|
-| `zed` | ~357 MB | Could contribute |
 | `pandoc` | ~213 MB | Could contribute |
 | `k9s` | ~178 MB | Could contribute |
-| `Sunshine` | ? | Could contribute |
-| `quickemu` | ? | |
+| `Sunshine` | ? | WIP: sysext created in community repo, pending PR |
 
 ## Quick Reference
 

mybox/Containerfile

@@ -22,10 +22,6 @@ RUN <<EORUN
 
     # Third-party repositories
     dnf config-manager addrepo --from-repofile=https://cli.github.com/packages/rpm/gh-cli.repo
-    dnf config-manager addrepo --from-repofile=https://download.docker.com/linux/fedora/docker-ce.repo
-    dnf config-manager addrepo --from-repofile=https://pkgs.tailscale.com/stable/fedora/tailscale.repo
-    dnf config-manager addrepo --from-repofile=https://github.com/terrapkg/subatomic-repos/raw/main/terra.repo
-    dnf install -y terra-release
 
     # 1Password CLI repository
     curl -fsSL https://downloads.1password.com/linux/keys/1password.asc -o /etc/pki/rpm-gpg/RPM-GPG-KEY-1password
@@ -86,11 +82,10 @@ RUN <<EORUN
         `# Virtualization (libvirt/qemu via sysext, see docs/SYSEXTS.md)` \
         virt-manager \
         \
-        `# Kubernetes / containers` \
-        docker-ce \
+        `# Kubernetes / containers (docker-ce via sysext, see docs/SYSEXTS.md)` \
         k9s \
         \
-        `# System administration` \
+        `# System administration (tailscale via sysext, see docs/SYSEXTS.md)` \
         age \
         apcupsd \
         chezmoi \
@@ -102,7 +97,6 @@ RUN <<EORUN
         etckeeper \
         nc \
         nfs-utils \
-        tailscale \
         tmux \
         \
         `# Desktop applications` \