fix(worker): keep interactive & planning prompts intact past Windows Terminal

wt.exe treats ';' as a command/tab delimiter in every argument, with no escape
that survives quoting (microsoft/terminal#13264), so a task description
containing ';' spawned extra terminals on "Run interactively" and planning start.
Route the launch as wt -> powershell -> claude and pass the free-text prompt via
$env:CLAUDEDO_LAUNCH_PROMPT so it never reaches the wt command line; PowerShell
binds the variable as a single argument (embedded quotes escaped for PS 5.1).

Also clarify the launcher, which serves interactive runs too (not just planning):
IPlanningTerminalLauncher -> ITerminalLauncher, WindowsTerminalPlanningLauncher ->
WindowsTerminalLauncher, LaunchStart/Resume -> LaunchPlanning{Start,Resume}Async.

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -102,7 +102,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     private readonly TaskResetService _resetService;
     private readonly TaskMergeService _mergeService;
     private readonly PlanningSessionManager _planning;
-    private readonly IPlanningTerminalLauncher _launcher;
+    private readonly ITerminalLauncher _launcher;
     private readonly PlanningAggregator _planningAggregator;
     private readonly PlanningMergeOrchestrator _planningMergeOrchestrator;
     private readonly PlanningChainCoordinator _planningChain;
@@ -127,7 +127,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         TaskResetService resetService,
         TaskMergeService mergeService,
         PlanningSessionManager planning,
-        IPlanningTerminalLauncher launcher,
+        ITerminalLauncher launcher,
         PlanningAggregator planningAggregator,
         PlanningMergeOrchestrator planningMergeOrchestrator,
         PlanningChainCoordinator planningChain,
@@ -533,9 +533,9 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         var ctx = await _planning.StartAsync(taskId, Context.ConnectionAborted);
         try
         {
-            await _launcher.LaunchStartAsync(ctx, Context.ConnectionAborted);
+            await _launcher.LaunchPlanningStartAsync(ctx, Context.ConnectionAborted);
         }
-        catch (PlanningLaunchException)
+        catch (TerminalLaunchException)
         {
             // Launch failed before any children could be created; force-cleanup is safe.
             await _planning.DiscardAsync(taskId, dequeueQueuedChildren: true, Context.ConnectionAborted);
@@ -548,7 +548,7 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     public async Task<PlanningSessionResumeContext> ResumePlanningSessionAsync(string taskId)
     {
         var ctx = await _planning.ResumeAsync(taskId, Context.ConnectionAborted);
-        await _launcher.LaunchResumeAsync(ctx, Context.ConnectionAborted);
+        await _launcher.LaunchPlanningResumeAsync(ctx, Context.ConnectionAborted);
         return ctx;
     }