Remove task-level approval system

Task-level approval (requiresApproval, mergeRequiresApproval,
pending_approval status) was redundant with executionMode
(yolo vs review_per_phase) and blocked the orchestrator's
phase completion flow. Tasks now complete directly;
phase-level review via executionMode is the right granularity.

Removed: schema columns (left in DB, removed from Drizzle),
TaskPendingApprovalEvent, approveTask/listPendingApprovals
procedures, findPendingApproval repository method, and all
frontend approval UI.

apps/server/db/repositories/drizzle/task.ts

@@ -4,7 +4,7 @@
  * Implements TaskRepository interface using Drizzle ORM.
  */
 
-import { eq, asc, and } from 'drizzle-orm';
+import { eq, asc } from 'drizzle-orm';
 import { nanoid } from 'nanoid';
 import type { DrizzleDatabase } from '../../index.js';
 import { tasks, taskDependencies, type Task } from '../../schema.js';
@@ -12,7 +12,6 @@ import type {
   TaskRepository,
   CreateTaskData,
   UpdateTaskData,
-  PendingApprovalFilters,
 } from '../task-repository.js';
 
 /**
@@ -77,26 +76,6 @@ export class DrizzleTaskRepository implements TaskRepository {
       .orderBy(asc(tasks.order));
   }
 
-  async findPendingApproval(filters?: PendingApprovalFilters): Promise<Task[]> {
-    const conditions = [eq(tasks.status, 'pending_approval')];
-
-    if (filters?.initiativeId) {
-      conditions.push(eq(tasks.initiativeId, filters.initiativeId));
-    }
-    if (filters?.phaseId) {
-      conditions.push(eq(tasks.phaseId, filters.phaseId));
-    }
-    if (filters?.category) {
-      conditions.push(eq(tasks.category, filters.category));
-    }
-
-    return this.db
-      .select()
-      .from(tasks)
-      .where(and(...conditions))
-      .orderBy(asc(tasks.createdAt));
-  }
-
   async update(id: string, data: UpdateTaskData): Promise<Task> {
     const [updated] = await this.db
       .update(tasks)

apps/server/db/repositories/index.ts

@@ -22,7 +22,6 @@ export type {
   TaskRepository,
   CreateTaskData,
   UpdateTaskData,
-  PendingApprovalFilters,
 } from './task-repository.js';
 
 export type {

apps/server/db/repositories/task-repository.ts

@@ -20,15 +20,6 @@ export type CreateTaskData = Omit<NewTask, 'id' | 'createdAt' | 'updatedAt'> & {
  */
 export type UpdateTaskData = Partial<CreateTaskData>;
 
-/**
- * Filters for finding pending approval tasks.
- */
-export interface PendingApprovalFilters {
-  initiativeId?: string;
-  phaseId?: string;
-  category?: TaskCategory;
-}
-
 /**
  * Task Repository Port
  *
@@ -70,13 +61,6 @@ export interface TaskRepository {
    */
   findByPhaseId(phaseId: string): Promise<Task[]>;
 
-  /**
-   * Find all tasks with status 'pending_approval'.
-   * Optional filters by initiative, phase, or category.
-   * Returns tasks ordered by createdAt.
-   */
-  findPendingApproval(filters?: PendingApprovalFilters): Promise<Task[]>;
-
   /**
    * Update a task.
    * Throws if task not found.