Disable records instead of deleting them

A disabled record stays in Jarl with its ID, TTL and comment but is
left out of the zone; the zone file lists it as a comment. Web UI
toggle, jarl record disable|enable, record.disable|enable operations
and API endpoints. Database schema 5.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/store/store.go

@@ -259,6 +259,10 @@ CREATE TABLE recovery_codes (
 	used_at TEXT,
 	PRIMARY KEY (user_id, code_hash)
 );
+`,
+	// 5: disabled records, kept but left out of the zone.
+	`
+ALTER TABLE records ADD COLUMN disabled INTEGER NOT NULL DEFAULT 0;
 `,
 }