fix(encyclopedia): tighten assign tests and first-paragraph handling

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/Wiki.Application/Encyclopedia/AssignNotesUseCase.cs

@@ -150,7 +150,12 @@ public sealed partial class AssignNotesUseCase(ITextModel model, EncyclopediaSet
             log.LogWarning("Dropping new article {Slug}: empty scope", slug);
             return null;
         }
-        return new PlannedArticle(slug, Text(o["titleDe"]) ?? slug, Text(o["titleEn"]) ?? slug, category, scope, []);
+        if (Text(o["titleDe"]) is not { } titleDe || Text(o["titleEn"]) is not { } titleEn)
+        {
+            log.LogWarning("Dropping new article {Slug}: missing title", slug);
+            return null;
+        }
+        return new PlannedArticle(slug, titleDe, titleEn, category, scope, []);
     }
 
     private static string? Text(JsonNode? n) =>
@@ -177,8 +182,8 @@ public sealed partial class AssignNotesUseCase(ITextModel model, EncyclopediaSet
     private static string FirstParagraph(string body)
     {
         var lines = body.Replace("\r", "").Split('\n')
-            .SkipWhile(l => l.Length == 0 || l.TrimStart().StartsWith('#'))
-            .TakeWhile(l => l.Trim().Length > 0);
+            .SkipWhile(l => string.IsNullOrWhiteSpace(l) || l.TrimStart().StartsWith('#'))
+            .TakeWhile(l => !string.IsNullOrWhiteSpace(l));
         var text = Flatten(string.Join(' ', lines)).Trim();
         return text.Length > FirstParagraphChars ? text[..FirstParagraphChars] : text;
     }

src/Wiki.Application/Encyclopedia/Prompts.cs

@@ -2,7 +2,7 @@ namespace Wiki.Application.Encyclopedia;
 
 /// <summary>
 /// Prompt texts of the encyclopedia. <see cref="Version"/> is bumped by hand whenever a prompt changes,
-/// so that a prompt fix retries earlier rejections and failed plans.
+/// so that a prompt fix retries earlier rejections and failed batches.
 /// </summary>
 public static class Prompts
 {

test/Wiki.Application.Tests/AssignNotesUseCaseTests.cs

@@ -103,7 +103,7 @@ public class AssignNotesUseCaseTests
     [Fact]
     public async Task Assign_Truncated_IsUnusable()
     {
-        var model = new FakeTextModel().Reply("""{"new":[],"notes":[""", truncated: true);
+        var model = new FakeTextModel().Reply("""{"new":[],"notes":[{"note":"a","skip":true}]}""", truncated: true);
 
         var outcome = await UseCase(model).AssignAsync(Batch("a"), [], ArticlePlan.Empty(), CancellationToken.None);
 
@@ -119,14 +119,53 @@ public class AssignNotesUseCaseTests
         var batch = Batch(Enumerable.Range(0, 20).Select(i => $"note-{i:00}").ToArray());
         var model = new FakeTextModel().Reply("""{"new":[],"notes":[]}""");
 
-        await UseCase(model).AssignAsync(batch, articles.Take(20).ToArray(), plan, CancellationToken.None);
+        await UseCase(model).AssignAsync(batch, articles.Take(100).ToArray(), plan, CancellationToken.None);
 
         var user = model.Calls[0].User;
         Assert.Equal(20, user.Split('\n').Count(l => l.StartsWith("note-")));
-        Assert.True(user.Split('\n').Count(l => l.StartsWith("article-")) <= 20);
+        Assert.Equal(20, user.Split('\n').Count(l => l.StartsWith("article-")));
         Assert.DoesNotContain("article-20 ", user);
     }
 
+    [Fact]
+    public async Task Assign_FirstParagraph_SkipsHeadingsAndBlankLines()
+    {
+        var note = PlanArticlesUseCaseTests.Note("a") with { Body = "# T\n\n  \nfirst line\ncontinued\n\nsecond para" };
+        var model = new FakeTextModel().Reply("""{"new":[],"notes":[]}""");
+
+        await UseCase(model).AssignAsync([note], [], ArticlePlan.Empty(), CancellationToken.None);
+
+        var line = model.Calls[0].User.Split('\n').Single(l => l.StartsWith("a | "));
+        Assert.EndsWith(" | first line continued", line);
+    }
+
+    [Fact]
+    public async Task Assign_FirstParagraph_CutTo300()
+    {
+        var note = PlanArticlesUseCaseTests.Note("a") with { Body = new string('y', 500) };
+        var model = new FakeTextModel().Reply("""{"new":[],"notes":[]}""");
+
+        await UseCase(model).AssignAsync([note], [], ArticlePlan.Empty(), CancellationToken.None);
+
+        var line = model.Calls[0].User.Split('\n').Single(l => l.StartsWith("a | "));
+        Assert.EndsWith(" | " + new string('y', 300), line);
+    }
+
+    [Fact]
+    public async Task Assign_NewWithoutTitle_Dropped()
+    {
+        var heating = Article("heating");
+        var model = new FakeTextModel().Reply("""
+            {"new":[{"slug":"garden","titleDe":"G","category":"room","scope":"s"}],
+             "notes":[{"note":"a","articles":["garden","heating"]}]}
+            """);
+
+        var outcome = await UseCase(model).AssignAsync(Batch("a"), [heating], PlanWith(heating), CancellationToken.None);
+
+        Assert.Empty(outcome.New);
+        Assert.Equal(["heating"], outcome.Assignments["a"]);
+    }
+
     [Fact]
     public async Task Assign_ModelUnavailable_Propagates()
     {