ref(installerconf): make VersionPrefixes a list, not a single string

Tag conventions can change across versions of the same project
(e.g. "jq-1.7.1" → bare "1.8.0"). A comma-separated list lets
the config express all historical prefixes. The parser tries each
in order and strips the first match.

Back-compat: singular "version_prefix" still works (parsed as a
single-element list).

internal/installerconf/installerconf.go

@@ -14,7 +14,7 @@
 //	source = github
 //	owner = jqlang
 //	repo = jq
-//	version_prefix = jq-
+//	version_prefixes = jq-
 //
 // With filename exclusions (hugo publishes _extended_ variants):
 //
@@ -73,9 +73,12 @@ type Conf struct {
 	// version string. Example: "tools/monorel/"
 	TagPrefix string
 
-	// VersionPrefix is stripped from version strings.
-	// Example: jq tags as "jq-1.7.1" → set to "jq-" to get "1.7.1".
-	VersionPrefix string
+	// VersionPrefixes are stripped from version/tag strings.
+	// Comma-separated. Each release tag is checked against these in order;
+	// the first match is stripped. Projects may change tag conventions across
+	// versions (e.g. "jq-1.7.1" in older releases, bare "1.8.0" later).
+	// Example: "jq-, cli-"
+	VersionPrefixes []string
 
 	// Exclude lists filename substrings to filter out.
 	// Assets whose name contains any of these are skipped.
@@ -116,7 +119,18 @@ func Read(path string) (*Conf, error) {
 	c.Owner = raw["owner"]
 	c.Repo = raw["repo"]
 	c.TagPrefix = raw["tag_prefix"]
-	c.VersionPrefix = raw["version_prefix"]
+
+	if v := raw["version_prefixes"]; v != "" {
+		for _, p := range strings.Split(v, ",") {
+			p = strings.TrimSpace(p)
+			if p != "" {
+				c.VersionPrefixes = append(c.VersionPrefixes, p)
+			}
+		}
+	} else if v := raw["version_prefix"]; v != "" {
+		// Back-compat with singular form.
+		c.VersionPrefixes = []string{v}
+	}
 
 	if v := raw["base_url"]; v != "" {
 		c.BaseURL = v
@@ -137,7 +151,7 @@ func Read(path string) (*Conf, error) {
 	known := map[string]bool{
 		"source": true, "owner": true, "repo": true,
 		"base_url": true, "url": true,
-		"tag_prefix": true, "version_prefix": true,
+		"tag_prefix": true, "version_prefix": true, "version_prefixes": true,
 		"exclude": true,
 	}
 	for k, v := range raw {

internal/installerconf/installerconf_test.go

@@ -18,21 +18,27 @@ repo = bat
 	assertEqual(t, "Owner", c.Owner, "sharkdp")
 	assertEqual(t, "Repo", c.Repo, "bat")
 	assertEqual(t, "TagPrefix", c.TagPrefix, "")
-	assertEqual(t, "VersionPrefix", c.VersionPrefix, "")
+	if len(c.VersionPrefixes) != 0 {
+		t.Errorf("VersionPrefixes = %v, want empty", c.VersionPrefixes)
+	}
 
 	if len(c.Exclude) != 0 {
 		t.Errorf("Exclude = %v, want empty", c.Exclude)
 	}
 }
 
-func TestVersionPrefix(t *testing.T) {
+func TestVersionPrefixes(t *testing.T) {
 	c := confFromString(t, `
 source = github
 owner = jqlang
 repo = jq
-version_prefix = jq-
+version_prefixes = jq-, cli-
 `)
-	assertEqual(t, "VersionPrefix", c.VersionPrefix, "jq-")
+	if len(c.VersionPrefixes) != 2 {
+		t.Fatalf("VersionPrefixes has %d items, want 2: %v", len(c.VersionPrefixes), c.VersionPrefixes)
+	}
+	assertEqual(t, "VersionPrefixes[0]", c.VersionPrefixes[0], "jq-")
+	assertEqual(t, "VersionPrefixes[1]", c.VersionPrefixes[1], "cli-")
 }
 
 func TestExclude(t *testing.T) {