feat(worker): resume a task's claude session in a terminal

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -575,6 +575,39 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     public Task OpenInteractiveTerminalAsync(string taskId) =>
         _interactive.StartAsync(taskId, Context.ConnectionAborted);
 
+    // Picks up a task's Claude session in a real terminal window (--resume) so the user can
+    // drive it by hand — distinct from OpenInteractiveTerminalAsync (the in-app streaming
+    // session). Only for tasks the worker isn't actively running, with a persisted session
+    // id and a live worktree.
+    public Task ResumeTaskInTerminal(string taskId) => HubGuard(async () =>
+    {
+        await using var ctx = await _dbFactory.CreateDbContextAsync();
+
+        var task = await new TaskRepository(ctx).GetByIdAsync(taskId, Context.ConnectionAborted)
+            ?? throw new KeyNotFoundException();
+        if (task.Status is TaskStatus.Running or TaskStatus.Queued)
+            throw new InvalidOperationException("Can't pick up a running or queued task — interrupt it first.");
+
+        var run = await new TaskRunRepository(ctx).GetLatestByTaskIdAsync(taskId, Context.ConnectionAborted);
+        if (run?.SessionId is not { Length: > 0 } sessionId)
+            throw new InvalidOperationException("This task has no resumable Claude session yet.");
+
+        var worktree = await new WorktreeRepository(ctx).GetByTaskIdAsync(taskId, Context.ConnectionAborted);
+        if (worktree is null || worktree.State is not (WorktreeState.Active or WorktreeState.Kept))
+            throw new InvalidOperationException("This task has no active worktree to resume in.");
+        if (!Directory.Exists(worktree.Path))
+            throw new InvalidOperationException("The task's worktree directory no longer exists.");
+
+        try
+        {
+            await _launcher.LaunchResumeAsync(worktree.Path, sessionId, Context.ConnectionAborted);
+        }
+        catch (TerminalLaunchException ex)
+        {
+            throw new InvalidOperationException(ex.Message);
+        }
+    });
+
     public Task SendInteractiveMessage(string taskId, string text) =>
         _interactive.SendAsync(taskId, text, Context.ConnectionAborted);
 

src/ClaudeDo.Worker/Planning/Interfaces/ITerminalLauncher.cs

@@ -7,6 +7,10 @@ public interface ITerminalLauncher
 {
     Task LaunchPlanningStartAsync(PlanningSessionStartContext ctx, CancellationToken cancellationToken);
     Task LaunchPlanningResumeAsync(PlanningSessionResumeContext ctx, CancellationToken cancellationToken);
+
+    // Resumes an arbitrary task's Claude session (--resume <id>) in a visible terminal so
+    // the user can pick up the conversation by hand — the "pick up in terminal" action.
+    Task LaunchResumeAsync(string workingDir, string claudeSessionId, CancellationToken cancellationToken);
 }
 
 public sealed class TerminalLaunchException : Exception

src/ClaudeDo.Worker/Planning/WindowsTerminalLauncher.cs

@@ -88,6 +88,26 @@ public sealed class WindowsTerminalLauncher : ITerminalLauncher
         return Task.CompletedTask;
     }
 
+    public Task LaunchResumeAsync(string workingDir, string claudeSessionId, CancellationToken cancellationToken)
+    {
+        if (!Directory.Exists(workingDir))
+            throw new TerminalLaunchException($"Working directory does not exist: {workingDir}");
+
+        var resolvedWt = ResolveWtOrThrow();
+        var resolvedClaude = ResolveClaudeOrThrow();
+
+        var command = BuildResumeCommand(resolvedClaude, claudeSessionId);
+
+        StartInWindowsTerminal(resolvedWt, workingDir, command, static _ => { });
+
+        return Task.CompletedTask;
+    }
+
+    // Resumes a session by id in default (interactive) permission mode: the user drives
+    // tool approvals in the terminal, unlike planning which pins --permission-mode plan.
+    internal static string BuildResumeCommand(string claudePath, string claudeSessionId) =>
+        BuildPwshCommand(claudePath, new[] { "--resume", claudeSessionId });
+
     // Builds the PowerShell command that launches an interactive planning session.
     // Arg order matters: variadic flags (--allowedTools, --add-dir) come first; the
     // single-line kickoff prompt is positional, so it must follow a single-value flag