fix(capacity): stabilize PTO flows and calendar consistency

Make PTO creation immediately approved, add PTO deletion, and ensure cache invalidation updates individual/team/revenue capacity consistently.

Harden holiday duplicate handling (422), support PTO-day availability overrides without disabling edits, and align tests plus OpenSpec artifacts with the new behavior.

backend/tests/Feature/TeamMember/TeamMemberTest.php

@@ -241,4 +241,35 @@ class TeamMemberTest extends TestCase
             'id' => $teamMember->id,
         ]);
     }
+
+    public function test_team_member_cache_is_invalidated_after_updates(): void
+    {
+        $token = $this->loginAsManager();
+        $role = Role::factory()->create();
+        $teamMember = TeamMember::factory()->create([
+            'role_id' => $role->id,
+            'active' => true,
+        ]);
+
+        $this->withHeader('Authorization', "Bearer {$token}")
+            ->getJson('/api/team-members?active=true')
+            ->assertStatus(200)
+            ->assertJsonCount(1, 'data');
+
+        $this->withHeader('Authorization', "Bearer {$token}")
+            ->putJson("/api/team-members/{$teamMember->id}", [
+                'active' => false,
+            ])
+            ->assertStatus(200);
+
+        $this->withHeader('Authorization', "Bearer {$token}")
+            ->getJson('/api/team-members?active=true')
+            ->assertStatus(200)
+            ->assertJsonCount(0, 'data');
+
+        $this->withHeader('Authorization', "Bearer {$token}")
+            ->getJson('/api/team-members?active=false')
+            ->assertStatus(200)
+            ->assertJsonCount(1, 'data');
+    }
 }