Fix CI: disambiguate TodoWorkflow reference and fix markdown lint headings

- Fully qualify TodoWorkflow as McpServer.McpAgent.Todo.TodoWorkflow in
  McpHostedAgentAdapterTests.cs to resolve CS0104 ambiguity with
  McpServer.Repl.Core.TodoWorkflow
- Convert bold emphasis to ### headings in docs/REPL-USER-GUIDE.md to
  fix 4 MD036/no-emphasis-as-heading lint errors

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: sharpninja

docs/REPL-USER-GUIDE.md

@@ -171,7 +171,7 @@ Session logging and turn management. Captures agent activity, reasoning dialog,
 - `workflow.sessionlog.appendActions` — Log actions performed
 - `workflow.sessionlog.queryHistory` — Query past sessions
 
-**Example: Open Session**
+### Example: Open Session
 
 ```yaml
 type: request
@@ -217,7 +217,7 @@ TODO item management with structured metadata, dependencies, and requirement tra
 - `workflow.todo.streamPlan` — Stream plan generation events
 - `workflow.todo.streamImplement` — Stream implementation execution
 
-**Example: Create TODO**
+### Example: Create TODO
 
 ```yaml
 type: request
@@ -276,7 +276,7 @@ Requirements management for functional (FR), technical (TR), and test (TEST) req
 - `workflow.requirements.generateDocument` — Generate formatted document
 - `workflow.requirements.ingestDocument` — Ingest external document
 
-**Example: List Functional Requirements**
+### Example: List Functional Requirements
 
 ```yaml
 type: request
@@ -334,7 +334,7 @@ Generic passthrough to all `McpServerClient` sub-clients. Enables dynamic invoca
 - `client.configuration.*` — Admin configuration
 - `client.tools.*` — Tool registry operations
 
-**Example: Context Search**
+### Example: Context Search
 
 ```yaml
 type: request

tests/McpServer.McpAgent.Tests/McpHostedAgentAdapterTests.cs

@@ -455,7 +455,7 @@ private static (McpHostedAgent HostedAgent, RecordingMcpHttpMessageHandler Handl
             });
         var identifiers = new McpSessionIdentifierFactory(options, timeProvider);
         var sessionLog = new McpServer.McpAgent.SessionLog.SessionLogWorkflow(client, identifiers, timeProvider);
-        var todo = new TodoWorkflow(client);
+        var todo = new McpServer.McpAgent.Todo.TodoWorkflow(client);
         var requirements = new RequirementsWorkflow(client.Requirements);
         var clientPassthrough = new GenericClientPassthrough(client);
         var replSessionLogAdapter = new SessionLogClientAdapter(client.SessionLog);