Add dismiss functionality for completed standalone tasksmakima/task-task-5dde682c-5dde682c

## Changes

### Backend
- Add 'hidden' field to Task model (models.rs)
- Add database migration for hidden column (20250122000000_add_task_hidden.sql)
- Update task listing queries to include hidden field and filter out hidden tasks
- Update update_task_for_owner to handle hidden field

### Frontend
- Add hidden field to TaskSummary interface (api.ts)
- Add dismissTask API function (api.ts)
- Add hideTask function to useTasks hook
- Add Dismiss button to TaskList for completed standalone tasks
- Wire up onDismiss handler in mesh.tsx route

## Behavior
- Completed standalone tasks (tasks without a contract) show a "Dismiss" button
- Dismissing a task sets hidden=true and removes it from the task list
- Hidden tasks are filtered out by default in all task listing queries

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/makima/frontend/src/lib/api.ts b/makima/frontend/src/lib/api.ts
index 86ff06c..b42a19f 100644
--- a/makima/frontend/src/lib/api.ts
+++ b/makima/frontend/src/lib/api.ts
@@ -543,6 +543,8 @@ export interface TaskSummary {
   subtaskCount: number;
   /** Whether this is a supervisor task (contract orchestrator) */
   isSupervisor: boolean;
+  /** Whether this task is hidden from the UI (user dismissed it) */
+  hidden: boolean;
   version: number;
   createdAt: string;
   updatedAt: string;
@@ -639,6 +641,8 @@ export interface UpdateTaskRequest {
   targetRepoPath?: string;
   /** Action on completion: "none", "branch", "merge", "pr" */
   completionAction?: CompletionAction;
+  /** Whether this task is hidden from the UI (user dismissed it) */
+  hidden?: boolean;
   version?: number;
 }
 
@@ -2631,3 +2635,15 @@ export function getSupervisorStatus(
     canResume,
   };
 }
+
+// =============================================================================
+// Task Dismiss (Hide) Functions
+// =============================================================================
+
+/**
+ * Dismiss (hide) a completed standalone task from the UI.
+ * This marks the task as hidden so it won't appear in the task list.
+ */
+export async function dismissTask(taskId: string): Promise<Task> {
+  return updateTask(taskId, { hidden: true });
+}