fix: remove legacy knowledge card tables and compatibility code

migrations/20260819_remove_sop_versions.sql

@@ -0,0 +1,134 @@
+-- Run this once on an existing MySQL database before deploying the
+-- single-version SOP application. It is intentionally explicit: the Go
+-- service only performs the data-preserving backfill and does not drop data.
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sops ADD COLUMN start_node_key VARCHAR(64) NOT NULL DEFAULT ''start''',
+    'SELECT 1')
+  FROM information_schema.columns
+  WHERE table_schema = DATABASE() AND table_name = 'sops' AND column_name = 'start_node_key'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+UPDATE sops s
+JOIN (
+  SELECT sop_id, MAX(id) AS version_id
+  FROM sop_versions
+  WHERE status = 'published'
+  GROUP BY sop_id
+) current ON current.sop_id = s.id
+JOIN sop_versions sv ON sv.id = current.version_id
+SET s.start_node_key = COALESCE(NULLIF(sv.start_node_key, ''), NULLIF(s.start_node_key, ''), 'start');
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sop_nodes ADD COLUMN sop_id BIGINT UNSIGNED NULL',
+    'SELECT 1')
+  FROM information_schema.columns
+  WHERE table_schema = DATABASE() AND table_name = 'sop_nodes' AND column_name = 'sop_id'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sop_edges ADD COLUMN sop_id BIGINT UNSIGNED NULL',
+    'SELECT 1')
+  FROM information_schema.columns
+  WHERE table_schema = DATABASE() AND table_name = 'sop_edges' AND column_name = 'sop_id'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sop_runs ADD COLUMN sop_id BIGINT UNSIGNED NULL',
+    'SELECT 1')
+  FROM information_schema.columns
+  WHERE table_schema = DATABASE() AND table_name = 'sop_runs' AND column_name = 'sop_id'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+UPDATE sop_nodes n JOIN sop_versions sv ON sv.id = n.sop_version_id
+SET n.sop_id = sv.sop_id WHERE n.sop_id IS NULL;
+UPDATE sop_edges e JOIN sop_versions sv ON sv.id = e.sop_version_id
+SET e.sop_id = sv.sop_id WHERE e.sop_id IS NULL;
+UPDATE sop_runs r JOIN sop_versions sv ON sv.id = r.sop_version_id
+SET r.sop_id = sv.sop_id WHERE r.sop_id IS NULL;
+
+-- A single-version SOP can only have one graph. Keep the latest published
+-- version's nodes and edges; remove historical graph rows after the backup.
+DELETE n
+FROM sop_nodes n
+JOIN sop_versions sv ON sv.id = n.sop_version_id
+JOIN (
+  SELECT sop_id, MAX(id) AS version_id
+  FROM sop_versions
+  WHERE status = 'published'
+  GROUP BY sop_id
+) current ON current.sop_id = sv.sop_id
+WHERE sv.id <> current.version_id;
+
+DELETE e
+FROM sop_edges e
+JOIN sop_versions sv ON sv.id = e.sop_version_id
+JOIN (
+  SELECT sop_id, MAX(id) AS version_id
+  FROM sop_versions
+  WHERE status = 'published'
+  GROUP BY sop_id
+) current ON current.sop_id = sv.sop_id
+WHERE sv.id <> current.version_id;
+
+ALTER TABLE sop_nodes MODIFY COLUMN sop_id BIGINT UNSIGNED NOT NULL;
+ALTER TABLE sop_edges MODIFY COLUMN sop_id BIGINT UNSIGNED NOT NULL;
+ALTER TABLE sop_runs MODIFY COLUMN sop_id BIGINT UNSIGNED NOT NULL;
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sop_nodes ADD INDEX idx_sop_nodes_sop_id (sop_id)',
+    'SELECT 1')
+  FROM information_schema.statistics
+  WHERE table_schema = DATABASE() AND table_name = 'sop_nodes' AND index_name = 'idx_sop_nodes_sop_id'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sop_edges ADD INDEX idx_sop_edges_sop_id (sop_id)',
+    'SELECT 1')
+  FROM information_schema.statistics
+  WHERE table_schema = DATABASE() AND table_name = 'sop_edges' AND index_name = 'idx_sop_edges_sop_id'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+SET @sql = (
+  SELECT IF(COUNT(*) = 0,
+    'ALTER TABLE sop_runs ADD INDEX idx_sop_runs_sop_id (sop_id)',
+    'SELECT 1')
+  FROM information_schema.statistics
+  WHERE table_schema = DATABASE() AND table_name = 'sop_runs' AND index_name = 'idx_sop_runs_sop_id'
+);
+PREPARE stmt FROM @sql;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+-- Verify the backfill before the destructive cleanup below.
+SELECT COUNT(*) AS nodes_without_sop FROM sop_nodes WHERE sop_id IS NULL;
+SELECT COUNT(*) AS edges_without_sop FROM sop_edges WHERE sop_id IS NULL;
+SELECT COUNT(*) AS runs_without_sop FROM sop_runs WHERE sop_id IS NULL;
+
+-- After the three counts above are all zero, remove the old version fields.
+-- The old columns/table are intentionally retained by this backfill step.
+-- Run 20260819_drop_sop_versions.sql only after all three counts above are 0.