perf(db): add missing indexes (appointment expiry, session dates, user status)

- appointments(status, expires_at): the per-minute expiry scheduler filtered on
  these with no covering index
- patient_sessions(created_at): dashboard revenue range scans
- users(status): admin user-list filter

PatientRecord(entity_type,entity_id) already covered by its unique constraint;
UserActiveContext.user_id is the PK — neither needed a new index.

migrations/Version20260628134241.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20260628134241 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Add missing indexes: appointments(status, expires_at) for the expiry scheduler, patient_sessions(created_at) for dashboard revenue ranges, users(status) for admin filters.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('CREATE INDEX idx_appointments_status_expires ON appointments (status, expires_at)');
+        $this->addSql('CREATE INDEX idx_patient_sessions_created_at ON patient_sessions (created_at)');
+        $this->addSql('CREATE INDEX idx_users_status ON users (status)');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP INDEX idx_appointments_status_expires ON appointments');
+        $this->addSql('DROP INDEX idx_patient_sessions_created_at ON patient_sessions');
+        $this->addSql('DROP INDEX idx_users_status ON users');
+    }
+}