Replace vendored docker-compose with podman-compose

podman-compose and docker-compose aren't discovered the same way by
`podman compose` - verified live (a fake-binary test reading podman's own
provider-search error output) that docker-compose is searched for by
exact path across a fixed list of CLI-plugin directories, while
podman-compose is instead looked up as a plain command on $PATH. This
package installs to /usr/local/bin/podman-compose accordingly, not under
any cli-plugins/ directory.

Unlike docker-compose (a single static Go binary), podman-compose is a
Python script with two runtime dependencies neither of which ship with
Unraid's own Python3 - PyYAML and python-dotenv, vendored here as plain
pure-Python source (no C extension build; PyYAML's own fallback handles
its optional C accelerator being absent).

Verified end-to-end on a real host: with the previous docker-compose
binary temporarily moved aside to confirm podman-compose was actually the
one invoked, `podman compose up/ps/down` ran a real compose project
correctly, including a live HTTP check against the started service.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

plugin/podman.plg

@@ -33,7 +33,7 @@
   Structure of this file:
     1. DOCTYPE entity block — plugin metadata + one version/file/md5 triple
        per package (the seven upstream components, catatonit/nftables/
-       docker-compose as vendored runtime dependencies, plus this
+       podman-compose as vendored runtime dependencies, plus this
        project's own "unraid-podman" scaffolding package, see
        packages/unraid-podman/).
        Entities are rewritten automatically by scripts/release.sh; never
@@ -122,12 +122,12 @@
 <!ENTITY nftables_txz_file    "nftables-&nftables_txz_version;-&pkgArch;-&pkgBuild;&pkgTag;.txz">
 <!ENTITY nftables_txz_md5     "00000000000000000000000000000000">
 
-<!-- docker-compose is the external Compose provider `podman compose`
-     shells out to (see packages/docker-compose/README.md) — without it
+<!-- podman-compose is the external Compose provider `podman compose`
+     shells out to (see packages/podman-compose/README.md) — without it
      every Compose panel action fails outright on a clean install. -->
-<!ENTITY docker_compose_txz_version "0.0.0">
-<!ENTITY docker_compose_txz_file    "docker-compose-&docker_compose_txz_version;-&pkgArch;-&pkgBuild;&pkgTag;.txz">
-<!ENTITY docker_compose_txz_md5     "00000000000000000000000000000000">
+<!ENTITY podman_compose_txz_version "0.0.0">
+<!ENTITY podman_compose_txz_file    "podman-compose-&podman_compose_txz_version;-&pkgArch;-&pkgBuild;&pkgTag;.txz">
+<!ENTITY podman_compose_txz_md5     "00000000000000000000000000000000">
 
 <!-- unraid-podman is this project's OWN scaffolding package (rc.podman,
      sbin/ scripts, event/ hooks, config templates — see
@@ -181,7 +181,7 @@ fi
 
 <!--
   The seven upstream component packages, plus catatonit, nftables, and
-  docker-compose (runtime dependencies vendored as-is — see the entity
+  podman-compose (runtime dependencies vendored as-is — see the entity
   block above for why). Each is downloaded straight into
   its backup slot under /boot/config/plugins/&name;/backup/packages/&version;/
   (grouped by PLUGIN version, not each component's own version — a rollback
@@ -275,12 +275,12 @@ fi
 </MD5>
 </FILE>
 
-<FILE Name="/boot/config/plugins/&name;/backup/packages/&version;/&docker_compose_txz_file;" Run="upgradepkg --install-new --reinstall">
+<FILE Name="/boot/config/plugins/&name;/backup/packages/&version;/&podman_compose_txz_file;" Run="upgradepkg --install-new --reinstall">
 <URL>
-&baseURL;/&docker_compose_txz_file;
+&baseURL;/&podman_compose_txz_file;
 </URL>
 <MD5>
-&docker_compose_txz_md5;
+&podman_compose_txz_md5;
 </MD5>
 </FILE>
 
@@ -345,7 +345,7 @@ echo "PASST_INSTALLED_VERSION=\"&passt_txz_version;\"" >> "$MANIFEST"
 echo "FUSE_OVERLAYFS_INSTALLED_VERSION=\"&fuse_overlayfs_txz_version;\"" >> "$MANIFEST"
 echo "CATATONIT_INSTALLED_VERSION=\"&catatonit_txz_version;\"" >> "$MANIFEST"
 echo "NFTABLES_INSTALLED_VERSION=\"&nftables_txz_version;\"" >> "$MANIFEST"
-echo "DOCKER_COMPOSE_INSTALLED_VERSION=\"&docker_compose_txz_version;\"" >> "$MANIFEST"
+echo "PODMAN_COMPOSE_INSTALLED_VERSION=\"&podman_compose_txz_version;\"" >> "$MANIFEST"
 echo "UNRAID_PODMAN_INSTALLED_VERSION=\"&unraid_podman_txz_version;\"" >> "$MANIFEST"
 
 echo "Seeding /boot/config/plugins/podman/ configuration (existing files left untouched)..."
@@ -408,7 +408,7 @@ removepkg &passt_txz_file;
 removepkg &fuse_overlayfs_txz_file;
 removepkg &catatonit_txz_file;
 removepkg &nftables_txz_file;
-removepkg &docker_compose_txz_file;
+removepkg &podman_compose_txz_file;
 removepkg &unraid_podman_txz_file;
 
 echo ""