fix(worker): surface the real reason a Claude run failed instead of a generic exit-code message

StreamAnalyzer now reads subtype/terminal_reason/errors from the CLI's result
event, and TaskRunner builds a specific ErrorMarkdown from them: max_turns names
the turn budget and points at set_task_config + requeue, api_error passes
through the provider's own message (which carries the reset time), and any
other terminal_reason is appended to the previous generic text instead of
staying invisible. Falls through to the old "exited with code N and no result"
text when there's no terminal_reason at all (a real crash).

tests/ClaudeDo.Worker.Tests/Runner/StreamAnalyzerTests.cs

@@ -153,6 +153,39 @@ public sealed class StreamAnalyzerTests
         Assert.Empty(analyzer.GetResult().Blocks);
     }
 
+    [Fact]
+    public void Extracts_Terminal_Reason_And_Errors_For_Max_Turns()
+    {
+        var analyzer = new StreamAnalyzer();
+        analyzer.ProcessLine("""{"type":"result","subtype":"error_max_turns","terminal_reason":"max_turns","errors":["Reached maximum number of turns (30)"],"session_id":"s1"}""");
+        var result = analyzer.GetResult();
+        Assert.Equal("max_turns", result.TerminalReason);
+        Assert.Equal("error_max_turns", result.ResultSubtype);
+        Assert.Single(result.Errors);
+        Assert.Equal("Reached maximum number of turns (30)", result.Errors[0]);
+    }
+
+    [Fact]
+    public void Extracts_Terminal_Reason_And_Result_Text_For_Api_Error()
+    {
+        var analyzer = new StreamAnalyzer();
+        analyzer.ProcessLine("""{"type":"result","terminal_reason":"api_error","result":"You've hit your session limit – resets 1pm (Europe/Berlin)","session_id":"s1"}""");
+        var result = analyzer.GetResult();
+        Assert.Equal("api_error", result.TerminalReason);
+        Assert.Contains("session limit", result.ResultMarkdown);
+    }
+
+    [Fact]
+    public void No_Terminal_Reason_Fields_Means_Null_And_Empty()
+    {
+        var analyzer = new StreamAnalyzer();
+        analyzer.ProcessLine("""{"type":"result","result":"done","session_id":"s1"}""");
+        var result = analyzer.GetResult();
+        Assert.Null(result.TerminalReason);
+        Assert.Null(result.ResultSubtype);
+        Assert.Empty(result.Errors);
+    }
+
     [Fact]
     public void Duplicate_Marker_In_Assistant_And_Result_Is_Collected_Once()
     {