feat: Remove checkpoint task types — per-phase review is sufficient

Checkpoint tasks (human-verify, decision, human-action) silently blocked
auto-dispatch with no UI to resolve them. Per-phase review + initiative
review already cover human verification, making checkpoints redundant.

Removed from: schema, dispatch manager, tRPC validators, detail prompt,
frontend types, tests, and docs.

apps/server/test/e2e/decompose-workflow.test.ts

@@ -143,7 +143,7 @@ describe('Detail Workflow E2E', () => {
       harness.setArchitectDetailComplete('detailer', [
         { number: 1, name: 'Task 1', content: 'First task', type: 'auto', dependencies: [] },
         { number: 2, name: 'Task 2', content: 'Second task', type: 'auto', dependencies: [1] },
-        { number: 3, name: 'Verify', content: 'Verify all', type: 'checkpoint:human-verify', dependencies: [2] },
+        { number: 3, name: 'Verify', content: 'Verify all', type: 'auto', dependencies: [2] },
       ]);
 
       // Resume with all answers
@@ -261,7 +261,7 @@ describe('Detail Workflow E2E', () => {
         tasks: [
           { number: 1, name: 'Schema', description: 'Create tables', type: 'auto', dependencies: [] },
           { number: 2, name: 'API', description: 'Create endpoints', type: 'auto', dependencies: [1] },
-          { number: 3, name: 'Verify', description: 'Test flow', type: 'checkpoint:human-verify', dependencies: [2] },
+          { number: 3, name: 'Verify', description: 'Test flow', type: 'auto', dependencies: [2] },
         ],
       });
 
@@ -271,33 +271,31 @@ describe('Detail Workflow E2E', () => {
       expect(tasks[0].name).toBe('Schema');
       expect(tasks[1].name).toBe('API');
       expect(tasks[2].name).toBe('Verify');
-      expect(tasks[2].type).toBe('checkpoint:human-verify');
+      expect(tasks[2].type).toBe('auto');
     });
 
-    it('should handle all task types', async () => {
+    it('should create tasks with auto type', async () => {
       const initiative = await harness.createInitiative('Task Types Test');
       const phases = await harness.createPhasesFromPlan(initiative.id, [
         { name: 'Phase 1' },
       ]);
       const detailTask = await harness.createDetailTask(phases[0].id, 'Mixed Tasks');
 
-      // Create tasks with all types
       await harness.caller.createChildTasks({
         parentTaskId: detailTask.id,
         tasks: [
           { number: 1, name: 'Auto Task', description: 'Automated work', type: 'auto' },
-          { number: 2, name: 'Human Verify', description: 'Visual check', type: 'checkpoint:human-verify', dependencies: [1] },
-          { number: 3, name: 'Decision', description: 'Choose approach', type: 'checkpoint:decision', dependencies: [2] },
-          { number: 4, name: 'Human Action', description: 'Manual step', type: 'checkpoint:human-action', dependencies: [3] },
+          { number: 2, name: 'Second Task', description: 'More work', type: 'auto', dependencies: [1] },
+          { number: 3, name: 'Third Task', description: 'Even more', type: 'auto', dependencies: [2] },
+          { number: 4, name: 'Final Task', description: 'Last step', type: 'auto', dependencies: [3] },
         ],
       });
 
       const tasks = await harness.getChildTasks(detailTask.id);
       expect(tasks).toHaveLength(4);
-      expect(tasks[0].type).toBe('auto');
-      expect(tasks[1].type).toBe('checkpoint:human-verify');
-      expect(tasks[2].type).toBe('checkpoint:decision');
-      expect(tasks[3].type).toBe('checkpoint:human-action');
+      for (const task of tasks) {
+        expect(task.type).toBe('auto');
+      }
     });
 
     it('should create task dependencies', async () => {
@@ -346,7 +344,7 @@ describe('Detail Workflow E2E', () => {
         { number: 1, name: 'Create user schema', content: 'Define User model', type: 'auto', dependencies: [] },
         { number: 2, name: 'Implement JWT', content: 'Token generation', type: 'auto', dependencies: [1] },
         { number: 3, name: 'Protected routes', content: 'Middleware', type: 'auto', dependencies: [2] },
-        { number: 4, name: 'Verify auth', content: 'Test login flow', type: 'checkpoint:human-verify', dependencies: [3] },
+        { number: 4, name: 'Verify auth', content: 'Test login flow', type: 'auto', dependencies: [3] },
       ]);
 
       await harness.caller.spawnArchitectDetail({
@@ -367,7 +365,7 @@ describe('Detail Workflow E2E', () => {
           { number: 1, name: 'Create user schema', description: 'Define User model', type: 'auto', dependencies: [] },
           { number: 2, name: 'Implement JWT', description: 'Token generation', type: 'auto', dependencies: [1] },
           { number: 3, name: 'Protected routes', description: 'Middleware', type: 'auto', dependencies: [2] },
-          { number: 4, name: 'Verify auth', description: 'Test login flow', type: 'checkpoint:human-verify', dependencies: [3] },
+          { number: 4, name: 'Verify auth', description: 'Test login flow', type: 'auto', dependencies: [3] },
         ],
       });
 
@@ -375,7 +373,7 @@ describe('Detail Workflow E2E', () => {
       const tasks = await harness.getChildTasks(detailTask.id);
       expect(tasks).toHaveLength(4);
       expect(tasks[0].name).toBe('Create user schema');
-      expect(tasks[3].type).toBe('checkpoint:human-verify');
+      expect(tasks[3].type).toBe('auto');
 
       // Agent should be idle
       const finalAgent = await harness.caller.getAgent({ name: 'detailer' });