feat(daily-prep): run daily prep from PrimeRunner via allowed MCP tools

tests/ClaudeDo.Worker.Tests/Prime/DailyPrepPromptTests.cs

@@ -0,0 +1,27 @@
+using ClaudeDo.Worker.Prime;
+
+namespace ClaudeDo.Worker.Tests.Prime;
+
+public class DailyPrepPromptTests
+{
+    [Fact]
+    public void Build_prompt_contains_cap_and_date()
+    {
+        var prompt = DailyPrepPrompt.BuildPrompt(maxTasks: 5, today: new DateOnly(2026, 6, 3));
+        Assert.Contains("5", prompt);
+        Assert.Contains("2026-06-03", prompt);
+        Assert.Contains("get_daily_prep_candidates", prompt);
+        Assert.Contains("set_my_day", prompt);
+    }
+
+    [Fact]
+    public void Build_args_allows_only_the_two_tools()
+    {
+        var args = DailyPrepPrompt.BuildArgs(maxTurns: 30);
+        Assert.Contains("--output-format stream-json", args);
+        Assert.Contains("--max-turns 30", args);
+        Assert.Contains("--allowedTools", args);
+        Assert.Contains("mcp__claudedo__get_daily_prep_candidates", args);
+        Assert.Contains("mcp__claudedo__set_my_day", args);
+    }
+}