started work on scheduling

db_init.php

@@ -13,7 +13,7 @@ if (defined('QDB_TEST_UPLOADS')) {
     define('QDB_LOCK', QDB_UPLOADS_DIR . '/.qdb_lock');
 }
 define('QDB_SCHEMA', __DIR__ . '/schema.sql');
-define('QDB_VERSION', 15);
+define('QDB_VERSION', 16);
 
 function qdb_table_exists(PDO $pdo, string $table): bool {
     $stmt = $pdo->prepare(
@@ -136,6 +136,22 @@ function qdb_apply_migrations(PDO $pdo, string $schemaSql): bool {
         }
     }
 
+    if (!qdb_table_exists($pdo, 'client_session_schedule')) {
+        $pdo->exec("
+            CREATE TABLE client_session_schedule (
+                clientCode           TEXT NOT NULL PRIMARY KEY,
+                scheduledDate        TEXT NOT NULL,
+                programCycleNumber   INTEGER NOT NULL,
+                programSessionNumber INTEGER NOT NULL,
+                programSessionID     TEXT,
+                updatedAt            INTEGER NOT NULL DEFAULT 0,
+                FOREIGN KEY(clientCode) REFERENCES client(clientCode) ON DELETE CASCADE
+            )
+        ");
+        $pdo->exec('CREATE INDEX IF NOT EXISTS idx_client_session_schedule_date ON client_session_schedule(scheduledDate)');
+        $changed = true;
+    }
+
     if (qdb_table_exists($pdo, 'questionnaire_structure_snapshot')
         && qdb_table_exists($pdo, 'questionnaire')) {
         require_once __DIR__ . '/lib/questionnaire_structure.php';