Read calendar event creators from the admin module, and archive the old ones (#14)

Reviewed-on: #14
Co-authored-by: Patrick Müller <mail@pmueller.me>
Co-committed-by: Patrick Müller <mail@pmueller.me>

docker/init/01-calendar-schema-dev.sql

@@ -1,5 +1,8 @@
 -- Local dev only. Real schema, provided directly by the repo owner
 -- (calendars, events, event_versions, sessions, users) - not a guess.
+-- Columns added by this repo's own migrations under sql/calendar/ are folded
+-- in here rather than appended, so a fresh dev container matches production
+-- after every migration has been applied. Keep the two in step.
 USE nachklang_calendar;
 
 CREATE TABLE `calendars` (
@@ -38,10 +41,16 @@ CREATE TABLE `events` (
   `calendar_id` int(11) NOT NULL,
   `uuid` text NOT NULL,
   `created_date` datetime DEFAULT current_timestamp(),
-  `created_by_id` int(11) NOT NULL,
+  -- Nullable since the cutover; see sql/calendar/003_allow_null_legacy_creator.sql.
+  `created_by_id` int(11) DEFAULT NULL,
+  -- Bridge to the admin module's user ids; see sql/calendar/001_add_admin_user_bridge.sql.
+  `created_by_user_id` varchar(36) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,
+  -- Archived creator name; see sql/calendar/002_snapshot_legacy_creator_names.sql.
+  `created_by_name` varchar(255) DEFAULT NULL,
   PRIMARY KEY (`event_id`),
   KEY `events_calendars_calendar_id_fk` (`calendar_id`),
   KEY `events_users_user_id_fk` (`created_by_id`),
+  KEY `events_created_by_user_idx` (`created_by_user_id`),
   CONSTRAINT `events_calendars_calendar_id_fk` FOREIGN KEY (`calendar_id`) REFERENCES `calendars` (`calendar_id`),
   CONSTRAINT `events_users_user_id_fk` FOREIGN KEY (`created_by_id`) REFERENCES `users` (`user_id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
@@ -58,11 +67,16 @@ CREATE TABLE `event_versions` (
   `location` text DEFAULT NULL,
   `url` text DEFAULT NULL,
   `version_created_by_id` int(11) DEFAULT NULL,
+  -- Bridge to the admin module's user ids; see sql/calendar/001_add_admin_user_bridge.sql.
+  `version_created_by_user_id` varchar(36) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL,
+  -- Archived editor name; see sql/calendar/002_snapshot_legacy_creator_names.sql.
+  `version_created_by_name` varchar(255) DEFAULT NULL,
   `status` text DEFAULT NULL,
   `version_created_at` datetime DEFAULT current_timestamp(),
   PRIMARY KEY (`event_version_id`),
   KEY `event_versions_events_event_id_fk` (`event_id`),
   KEY `event_versions_users_user_id_fk` (`version_created_by_id`),
+  KEY `event_versions_created_by_user_idx` (`version_created_by_user_id`),
   CONSTRAINT `event_versions_events_event_id_fk` FOREIGN KEY (`event_id`) REFERENCES `events` (`event_id`) ON DELETE CASCADE ON UPDATE CASCADE,
   CONSTRAINT `event_versions_users_user_id_fk` FOREIGN KEY (`version_created_by_id`) REFERENCES `users` (`user_id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;
@@ -78,12 +92,16 @@ INSERT INTO calendars (calendar_id, name, includes_calendars) VALUES
 INSERT INTO users (email, password_hash, full_name, is_active) VALUES
     ('dev@nachklang.art', '$2b$10$vmj7POS/68SGE.eI7pGjMegrw0vNNZ2HVSUTra5NRsl8iOLwiMgZK', 'Dev Admin', 1);
 
-INSERT INTO events (calendar_id, uuid, created_by_id) VALUES
-    (1, UUID(), 1),
-    (1, UUID(), 1),
-    (1, UUID(), 1);
+-- Two rows are left on the legacy path and one carries an admin user id, so
+-- dev exercises both branches of the step 3 dual-read rather than only the
+-- happy one. It is deliberately a PUBLIC event, so the anonymous listing the
+-- website uses covers both. The id is the dev admin from 04-admin-schema.sql.
+INSERT INTO events (calendar_id, uuid, created_by_id, created_by_user_id, created_by_name) VALUES
+    (1, UUID(), 1, NULL, 'Dev Admin'),
+    (1, UUID(), 1, 'dev-user-0000-0000-0000-000000000001', NULL),
+    (1, UUID(), 1, NULL, 'Dev Admin');
 
-INSERT INTO event_versions (event_id, name, description, start_datetime, end_datetime, whole_day, location, url, status, version_created_by_id) VALUES
-    (1, 'Frühlingskonzert 2026', 'Erstes Konzert der Reihe', '2026-04-18 19:00:00', '2026-04-18 21:00:00', 0, 'Musikhochschule, Karlsruhe', 'https://www.nachklang.art/events/fruehlingskonzert-2026', 'PUBLIC', 1),
-    (2, 'Sommerkonzert 2026', 'Zweites Konzert der Reihe', '2026-07-11 19:00:00', '2026-07-11 21:00:00', 0, 'Christuskirche, Karlsruhe', 'https://www.nachklang.art/events/sommerkonzert-2026', 'PUBLIC', 1),
-    (3, 'Adventskonzert 2026', 'Drittes Konzert der Reihe', '2026-12-05 19:00:00', '2026-12-05 21:00:00', 0, 'Stadtkirche, Karlsruhe', 'https://www.nachklang.art/events/adventskonzert-2026', 'DRAFT', 1);
+INSERT INTO event_versions (event_id, name, description, start_datetime, end_datetime, whole_day, location, url, status, version_created_by_id, version_created_by_user_id, version_created_by_name) VALUES
+    (1, 'Frühlingskonzert 2026', 'Erstes Konzert der Reihe', '2026-04-18 19:00:00', '2026-04-18 21:00:00', 0, 'Musikhochschule, Karlsruhe', 'https://www.nachklang.art/events/fruehlingskonzert-2026', 'PUBLIC', 1, NULL, 'Dev Admin'),
+    (2, 'Sommerkonzert 2026', 'Zweites Konzert der Reihe', '2026-07-11 19:00:00', '2026-07-11 21:00:00', 0, 'Christuskirche, Karlsruhe', 'https://www.nachklang.art/events/sommerkonzert-2026', 'PUBLIC', 1, 'dev-user-0000-0000-0000-000000000001', NULL),
+    (3, 'Adventskonzert 2026', 'Drittes Konzert der Reihe', '2026-12-05 19:00:00', '2026-12-05 21:00:00', 0, 'Stadtkirche, Karlsruhe', 'https://www.nachklang.art/events/adventskonzert-2026', 'DRAFT', 1, NULL, 'Dev Admin');