feat(tasks): mark tasks and lists as manual

Reminders written down as todos had no home: every task looked like Claude work.
A manual task now shows a MANUAL badge and hides send-to-queue, refine and the
planning session; the queue picker, daily prep and the list handler all skip it,
with a TaskStateService guard so the MCP surface and hub cannot start one either.
Opening a hand-driven ConPTY session stays available on purpose.

A list can be marked manual in its settings, which makes tasks created there
(UI and MCP add_task) start out manual. Toggle per task from its context menu.

src/ClaudeDo.Worker/Queue/QueuePicker.cs

@@ -15,7 +15,7 @@ public sealed class QueuePicker : IQueuePicker
     {
         // Atomic queue claim: UPDATE + RETURNING in a single statement prevents TOCTOU races.
         // Raw SQL because EF cannot express UPDATE...RETURNING.
-        // Eligible task must be Queued, unblocked, and due (or unscheduled).
+        // Eligible task must be Queued, unblocked, not manual, and due (or unscheduled).
         // EF SQLite stores DateTime as "yyyy-MM-dd HH:mm:ss.fffffff" — same format used here for comparison.
         await using var ctx = await _dbFactory.CreateDbContextAsync(ct);
         var nowStr = now.ToUniversalTime().ToString("yyyy-MM-dd HH:mm:ss.fffffff");
@@ -27,6 +27,7 @@ public sealed class QueuePicker : IQueuePicker
                 SELECT t.id FROM tasks t
                 WHERE t.status = 'queued'
                   AND t.blocked_by_task_id IS NULL
+                  AND t.is_manual = 0
                   AND (t.scheduled_for IS NULL OR t.scheduled_for <= {0})
                 ORDER BY t.sort_order ASC, t.created_at ASC
                 LIMIT 1