feat(runner): mint per-run MCP token + emit run-scoped --mcp-config

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ClaudeDo.Worker/Runner/ClaudeArgsBuilder.cs

@@ -8,7 +8,9 @@ public sealed record ClaudeRunConfig(
     string? AgentPath,
     string? ResumeSessionId,
     int? MaxTurns = null,
-    string? PermissionMode = null
+    string? PermissionMode = null,
+    string? McpConfigPath = null,
+    string? AllowedTools = null
 );
 
 public sealed class ClaudeArgsBuilder
@@ -57,6 +59,12 @@ public sealed class ClaudeArgsBuilder
 
         args.Add($"--json-schema {Escape(ResultSchema)}");
 
+        if (config.McpConfigPath is not null)
+            args.Add($"--mcp-config {Escape(config.McpConfigPath)}");
+
+        if (config.AllowedTools is not null)
+            args.Add($"--allowedTools {config.AllowedTools}");
+
         if (config.ResumeSessionId is not null)
             args.Add($"--resume {config.ResumeSessionId}");
 

src/ClaudeDo.Worker/Runner/TaskRunner.cs

@@ -1,3 +1,4 @@
+using System.Text.Json;
 using ClaudeDo.Data;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
@@ -19,6 +20,7 @@ public sealed class TaskRunner
     private readonly WorkerConfig _cfg;
     private readonly ILogger<TaskRunner> _logger;
     private readonly ITaskStateService _state;
+    private readonly TaskRunTokenRegistry _tokens;
 
     public TaskRunner(
         IClaudeProcess claude,
@@ -28,7 +30,8 @@ public sealed class TaskRunner
         ClaudeArgsBuilder argsBuilder,
         WorkerConfig cfg,
         ILogger<TaskRunner> logger,
-        ITaskStateService state)
+        ITaskStateService state,
+        TaskRunTokenRegistry tokens)
     {
         _claude = claude;
         _dbFactory = dbFactory;
@@ -38,10 +41,13 @@ public sealed class TaskRunner
         _cfg = cfg;
         _logger = logger;
         _state = state;
+        _tokens = tokens;
     }
 
     public async Task RunAsync(TaskEntity task, string slot, CancellationToken ct)
     {
+        string? mcpToken = null;
+        string? mcpConfigPath = null;
         try
         {
             ListEntity? list;
@@ -75,6 +81,22 @@ public sealed class TaskRunner
 
             var resolvedConfig = await ResolveConfigAsync(task, listConfig, null, ct);
 
+            // Improvement-eligible runs get a per-run MCP identity so the agent can file
+            // out-of-scope follow-ups via SuggestImprovement. Children and planning runs do not.
+            if (task.ParentTaskId is null && task.PlanningPhase == PlanningPhase.None)
+            {
+                mcpToken = TaskRunTokenRegistry.GenerateToken();
+                _tokens.Register(mcpToken, task.Id);
+                Directory.CreateDirectory(_cfg.LogRoot);
+                mcpConfigPath = Path.Combine(_cfg.LogRoot, $"{task.Id}_mcp.json");
+                await File.WriteAllTextAsync(mcpConfigPath, BuildRunMcpConfigJson(mcpToken), ct);
+                resolvedConfig = resolvedConfig with
+                {
+                    McpConfigPath = mcpConfigPath,
+                    AllowedTools = "mcp__claudedo_run__SuggestImprovement",
+                };
+            }
+
             var now = DateTime.UtcNow;
             await _state.StartRunningAsync(task.Id, now, ct);
             await _broadcaster.TaskStarted(slot, task.Id, now);
@@ -135,6 +157,15 @@ public sealed class TaskRunner
             _logger.LogError(ex, "Unhandled exception running task {TaskId}", task.Id);
             await MarkFailed(task.Id, task.Title, slot, $"Unhandled error: {ex.Message}");
         }
+        finally
+        {
+            if (mcpToken is not null)
+            {
+                _tokens.Unregister(mcpToken);
+                if (mcpConfigPath is not null)
+                    try { File.Delete(mcpConfigPath); } catch { /* best effort */ }
+            }
+        }
     }
 
     public async Task ContinueAsync(string taskId, string followUpPrompt, string slot, CancellationToken ct)
@@ -396,6 +427,26 @@ public sealed class TaskRunner
         }
     }
 
+    private string BuildRunMcpConfigJson(string token)
+    {
+        var payload = new
+        {
+            mcpServers = new
+            {
+                claudedo_run = new
+                {
+                    type = "http",
+                    url = $"http://127.0.0.1:{_cfg.SignalRPort}/mcp",
+                    headers = new Dictionary<string, string>
+                    {
+                        ["Authorization"] = $"Bearer {token}",
+                    },
+                },
+            },
+        };
+        return JsonSerializer.Serialize(payload, new JsonSerializerOptions { WriteIndented = true });
+    }
+
     private async Task<ClaudeRunConfig> ResolveConfigAsync(
         TaskEntity task, ListConfigEntity? listConfig, string? resumeSessionId, CancellationToken ct)
     {