ci: version from the tag or the commits since it; dev images from main gated on tests; recognise -dev. tags [CI SKIP]

backend/src/MoShiro.Backend.Application/Updates/BackendUpdates.cs

@@ -55,9 +55,14 @@ public sealed class BackendUpdates : IHostedService
             return "release";
         }
 
-        return BuildInfo.Tag is { } tag && (tag.StartsWith("dev-", StringComparison.Ordinal) || tag.StartsWith("main-", StringComparison.Ordinal)) ? "dev" : "release";
+        return IsDevTag(BuildInfo.Tag) ? "dev" : "release";
     }
 
+    /// <summary>开发构建的 tag：新格式 v0.4.1-dev.12-abc1234（含 -dev.），以及旧的 dev-&lt;sha&gt;、main-&lt;sha&gt;。</summary>
+    public static bool IsDevTag(string? tag) =>
+        tag is not null
+        && (tag.Contains("-dev.", StringComparison.Ordinal) || tag.StartsWith("dev-", StringComparison.Ordinal) || tag.StartsWith("main-", StringComparison.Ordinal));
+
     public async ValueTask<BackendUpdateView> GetAsync(CancellationToken ct)
     {
         string channel = ChannelOf(_options);

backend/tests/MoShiro.Backend.Tests/BackendUpdateTests.cs

@@ -30,6 +30,18 @@ public sealed class BackendUpdateTests : IAsyncLifetime
         Assert.Equal(expected, BackendUpdates.ChannelOf(new BackendOptions { UpdateChannel = "auto", ImageNamespace = imageNamespace }));
     }
 
+    [Theory]
+    [InlineData("v0.4.1-dev.12-044ce0c", true)]
+    [InlineData("dev-725fe17a7de8", true)]
+    [InlineData("main-725fe17a7d", true)]
+    [InlineData("v0.4.0", false)]
+    [InlineData("v0.4.1-rc.1", false)]
+    [InlineData(null, false)]
+    public void IsDevTag_RecognisesDevelopmentBuilds(string? tag, bool expected)
+    {
+        Assert.Equal(expected, BackendUpdates.IsDevTag(tag));
+    }
+
     private async Task<HttpResponseMessage> PublishAsync(long seq, string channel = "dev")
     {
         string manifest = $$"""{"component":"backend","channel":"{{channel}}","image":"registry.example/moshiro-{{channel}}/moshiro-backend","digest":"{{Digest}}","tag":"{{channel}}-{{seq}}","version":"0.1.1","seq":{{seq}}}""";