Make agent file writes append by default

MeetingAssistant.Tests/MeetingSummaryToolTests.cs

@@ -503,12 +503,42 @@ public sealed class MeetingSummaryToolTests
             """);
         var tools = new MeetingSummaryTools(artifacts);
 
+        await tools.WriteContext("appended");
         await tools.WriteContext("inserted", insert: 2);
         await tools.WriteContext("replacement", from: 1, to: 1);
 
         var context = await File.ReadAllTextAsync(artifacts.AssistantContextPath);
         Assert.Contains("state: summarizing", context);
-        Assert.Contains("replacement\ninserted\nline two", context);
+        Assert.Contains("replacement\ninserted\nline two\nappended", context);
+    }
+
+    [Fact]
+    public async Task ToolsReplaceAssistantContextBodyOnlyWhenRequested()
+    {
+        var root = Path.Combine(Path.GetTempPath(), "meeting-assistant-tests", Guid.NewGuid().ToString("N"));
+        var artifacts = new MeetingSessionArtifacts(
+            MeetingNotePath: Path.Combine(root, "Meetings", "Notes", "meeting.md"),
+            TranscriptPath: Path.Combine(root, "Meetings", "Transcripts", "transcript.md"),
+            AssistantContextPath: Path.Combine(root, "Meetings", "Assistant Context", "context.md"),
+            SummaryPath: Path.Combine(root, "Meetings", "Summaries", "summary.md"));
+        Directory.CreateDirectory(Path.GetDirectoryName(artifacts.AssistantContextPath)!);
+        await File.WriteAllTextAsync(
+            artifacts.AssistantContextPath,
+            """
+            ---
+            state: summarizing
+            ---
+
+            line one
+            """);
+        var tools = new MeetingSummaryTools(artifacts);
+
+        await tools.WriteContext("replacement", replace_file: true);
+
+        var context = await File.ReadAllTextAsync(artifacts.AssistantContextPath);
+        Assert.Contains("state: summarizing", context);
+        Assert.Contains("replacement", context);
+        Assert.DoesNotContain("line one", context);
     }
 
     [Fact]
@@ -561,7 +591,8 @@ public sealed class MeetingSummaryToolTests
             # Assistant Context
 
             ## Live Context
-            """);
+            """,
+            replace_file: true);
 
         var context = await File.ReadAllTextAsync(artifacts.AssistantContextPath);
         Assert.Contains("state: summarizing", context);

MeetingAssistant.Tests/ProjectKnowledgeToolTests.cs

@@ -57,14 +57,14 @@ public sealed class ProjectKnowledgeToolTests
         Assert.Equal("MeetingAssistant/notes/summary.md", writeResult);
         Assert.Equal("# Project Update", await File.ReadAllTextAsync(Path.Combine(meetingAssistantRoot, "notes", "summary.md")));
         Assert.Equal("IgnoredProject/ignored.md", await tools.WriteProjectFile("IgnoredProject", "ignored.md", "changed"));
-        Assert.Equal("changed", await File.ReadAllTextAsync(Path.Combine(ignoredRoot, "ignored.md")));
+        Assert.Equal("alpha should not be searched\nchanged", await File.ReadAllTextAsync(Path.Combine(ignoredRoot, "ignored.md")));
         Assert.Equal(
             "README.md:2 Second alpha line",
             await tools.Search("alpha"));
     }
 
     [Fact]
-    public async Task WriteProjectFileSupportsOverwriteReplaceInsertAndCreate()
+    public async Task WriteProjectFileSupportsAppendReplaceInsertOverwriteAndCreate()
     {
         var root = Path.Combine(Path.GetTempPath(), "meeting-assistant-tests", Guid.NewGuid().ToString("N"));
         var projectsRoot = Path.Combine(root, "Projects");
@@ -88,6 +88,12 @@ public sealed class ProjectKnowledgeToolTests
         await tools.WriteProjectFile("MeetingAssistant", "notes.md", "inserted", insert: 2);
         Assert.Equal("one\ninserted\nTWO\nTHREE\nfour", await File.ReadAllTextAsync(projectFile));
 
+        await tools.WriteProjectFile("MeetingAssistant", "notes.md", "appended");
+        Assert.Equal("one\ninserted\nTWO\nTHREE\nfour\nappended", await File.ReadAllTextAsync(projectFile));
+
+        await tools.WriteProjectFile("MeetingAssistant", "notes.md", "replacement", replace_file: true);
+        Assert.Equal("replacement", await File.ReadAllTextAsync(projectFile));
+
         await tools.WriteProjectFile("MeetingAssistant", "created/new.md", "created content");
         Assert.Equal("created content", await File.ReadAllTextAsync(Path.Combine(projectRoot, "created", "new.md")));
     }
@@ -112,6 +118,7 @@ public sealed class ProjectKnowledgeToolTests
         Assert.StartsWith("Refused:", await tools.WriteProjectFile("MeetingAssistant", "../outside.md", "content"));
         Assert.StartsWith("Refused:", await tools.WriteProjectFile("MeetingAssistant", "notes.md", "content", from: 1));
         Assert.StartsWith("Refused:", await tools.WriteProjectFile("MeetingAssistant", "notes.md", "content", from: 1, to: 1, insert: 1));
+        Assert.StartsWith("Refused:", await tools.WriteProjectFile("MeetingAssistant", "notes.md", "content", from: 1, to: 1, replace_file: true));
     }
 
     private static MeetingSessionArtifacts CreateArtifacts(string root)

MeetingAssistant.Tests/WorkflowRulesEditorTests.cs

@@ -82,6 +82,46 @@ public sealed class WorkflowRulesEditorTests
         Assert.DoesNotContain("other.yaml", searchResult);
     }
 
+    [Fact]
+    public async Task RulesEditorToolsAppendByDefaultAndReplaceOnlyWhenRequested()
+    {
+        var root = Path.Combine(Path.GetTempPath(), "meeting-assistant-tests", Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(root);
+        var rulesPath = Path.Combine(root, "rules.yaml");
+        await File.WriteAllTextAsync(
+            rulesPath,
+            """
+            rules:
+            - name: existing
+              on:
+                - created: {}
+              steps:
+                - uses: add_attendee
+                  value: Ada
+            """);
+        var tools = new WorkflowRulesEditorTools(new MeetingAssistantOptions
+        {
+            Automation = new AutomationOptions { RulesPath = rulesPath }
+        });
+
+        await tools.WriteRules("""
+            - name: appended
+              on:
+                - created: {}
+              steps:
+                - uses: add_attendee
+                  value: Grace
+            """);
+
+        var appended = await File.ReadAllTextAsync(rulesPath);
+        Assert.Contains("name: existing", appended);
+        Assert.Contains("name: appended", appended);
+
+        await tools.WriteRules("rules: []", replace_file: true);
+
+        Assert.Equal("rules: []", await File.ReadAllTextAsync(rulesPath));
+    }
+
     [Fact]
     public async Task RulesEditorToolsRefuseInvalidYamlWithoutOverwritingFile()
     {
@@ -94,7 +134,7 @@ public sealed class WorkflowRulesEditorTests
             Automation = new AutomationOptions { RulesPath = rulesPath }
         });
 
-        var result = await tools.WriteRules("rules:\n- name: [");
+        var result = await tools.WriteRules("rules:\n- name: [", replace_file: true);
 
         Assert.StartsWith("Refused: workflow rules YAML is invalid.", result);
         Assert.Equal("rules: []", await File.ReadAllTextAsync(rulesPath));