fix(void): use concrete release-download URL for xbps client registration

Replace the self-referential <repo-url-from-release-notes> placeholder
in the root README, the release-notes template, and the Void packaging
README with the concrete per-tag download prefix the build-xbps job
attaches the signed repo to. Static docs default TAG to the current
version; release.yml renders github.ref_name at publish time.

Fixes #29

.github/workflows/release.yml

@@ -298,7 +298,7 @@ jobs:
             ```bash
             # as root (the files come from this release's assets):
             cp <fingerprint>.plist /var/db/xbps/keys/
-            echo 'repository=<repo-url-from-release-notes>' > /etc/xbps.d/voculinux.conf
+            echo 'repository=https://github.com/${{ github.repository }}/releases/download/${{ github.ref_name }}/' > /etc/xbps.d/voculinux.conf
             sudo xbps-install -Sy voculinux
             ```
             Answer `Y` at the fingerprint prompt only after checking it

README.md

@@ -250,7 +250,8 @@ templates in `packaging/void/srcpkgs/`. Details: [packaging/void/README.md](pack
 ```bash
 # as root on the Void system (the files come from the release assets):
 cp <fingerprint>.plist /var/db/xbps/keys/
-echo 'repository=<repo-url-from-release-notes>' > /etc/xbps.d/voculinux.conf
+TAG=v0.18.5  # match the release you install from
+echo "repository=https://github.com/VocaHQ/vocalinux/releases/download/${TAG}/" > /etc/xbps.d/voculinux.conf
 ```
 
 Prefer the release notes for the exact repository URL. On first sync,

packaging/void/README.md

@@ -172,7 +172,8 @@ openssl genrsa -out xbps-sign-key.pem 4096
 ```sh
 # as root on the Void system (the release notes carry the repo URL):
 cp <fingerprint>.plist /var/db/xbps/keys/
-echo 'repository=<repo-url-from-release-notes>' > /etc/xbps.d/voculinux.conf
+TAG=v0.18.5  # match the release you install from
+echo "repository=https://github.com/VocaHQ/vocalinux/releases/download/${TAG}/" > /etc/xbps.d/voculinux.conf
 xbps-install -Sy voculinux
 ```
 

tests/test_void_signed_repo.py

@@ -266,6 +266,37 @@ def test_release_workflow_attaches_signed_repo_to_release() -> None:
         assert marker in text, f"the xbps job must attach {marker} to the release"
 
 
+#: Concrete release-download prefix every client snippet must name. The
+#: xbps job attaches the signed repo flat to the tag release with
+#: ``gh release upload "${{ github.ref_name }}"``, so the repository URL is
+#: the per-tag download prefix below.
+CONCRETE_REPO_DOWNLOAD = "https://github.com/VocaHQ/vocalinux/releases/download/"
+
+
+def test_client_registration_names_concrete_repo_url() -> None:
+    """No self-referential placeholder: every client snippet names the
+    concrete release-download URL the xbps job attaches the repo to."""
+    workflow = _release_workflow_text()
+    root = ROOT_README.read_text(encoding="utf-8")
+    void_readme = README.read_text(encoding="utf-8")
+    for name, text in (
+        ("release.yml", workflow),
+        ("README.md", root),
+        ("packaging/void/README.md", void_readme),
+    ):
+        assert (
+            "<repo-url-from-release-notes>" not in text
+        ), f"{name} still carries the self-referential repo-URL placeholder"
+        assert "repository=<" not in text, f"{name} still carries a placeholder repository URL"
+    assert CONCRETE_REPO_DOWNLOAD in root, "root README must name the concrete release download URL"
+    assert (
+        CONCRETE_REPO_DOWNLOAD in void_readme
+    ), "void README must name the concrete release download URL"
+    assert (
+        "releases/download/${{ github.ref_name }}" in workflow
+    ), "release.yml must render the concrete per-tag download URL at publish time"
+
+
 def test_root_readme_registers_the_void_repo() -> None:
     """Root README: Void install from the signed repo, not just the track README."""
     text = ROOT_README.read_text(encoding="utf-8")