fix: run DDL migration guard on the script editor Test button

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/Editor.svelte

@@ -223,12 +223,21 @@
 	)
 	let ddlGuard = $state<DdlMigrationGuard | undefined>(undefined)
 
-	async function runCmdEnterWithDdlGuard() {
+	// Run the DDL migration guard against the current code. Returns false when the
+	// user cancels (the run must be aborted); may rewrite the code (migrated
+	// statements stripped). Exported so run paths that bypass the Monaco
+	// Cmd+Enter binding (e.g. the Test button) can guard too.
+	export async function guardDdlBeforeRun(): Promise<boolean> {
 		if (datatableForMigrations && ddlGuard) {
 			const res = await ddlGuard.guard(getCode())
-			if (!res.proceed) return
+			if (!res.proceed) return false
 			if (res.code !== getCode()) setCode(res.code)
 		}
+		return true
+	}
+
+	async function runCmdEnterWithDdlGuard() {
+		if (!(await guardDdlBeforeRun())) return
 		cmdEnterAction?.()
 	}
 

frontend/src/lib/components/ScriptEditor.svelte

@@ -743,7 +743,17 @@
 		args = nargs
 	}
 
-	export async function runTest(opts?: { cascade?: boolean }) {
+	export async function runTest(opts?: { cascade?: boolean; skipDdlGuard?: boolean }) {
+		// Intercept DDL statements (offer to turn them into data table migrations)
+		// on every run path, not just the editor's Cmd+Enter. `skipDdlGuard` is set
+		// by the Cmd+Enter action, which already guarded before calling us.
+		if (!opts?.skipDdlGuard) {
+			if ((await editor?.guardDdlBeforeRun()) === false) return
+			// The guard may have rewritten the code (migrated statements stripped);
+			// `editorCode` is kept in sync by the editor binding, so mirror the
+			// on:change handler and pull it into `code` before we run.
+			if (activeModuleTab === null) code = editorCode
+		}
 		// When the caller forces a cascade choice (e.g. the canvas runnable
 		// menu's "Run + trigger N downstream"), also flip the persistent
 		// `cascadeDownstream` state so the split button's label/icon reflect
@@ -2626,7 +2636,8 @@
 				} else {
 					await inferModuleSchema()
 				}
-				runTest()
+				// The Editor already ran the DDL guard before invoking this action.
+				runTest({ skipDdlGuard: true })
 			}}
 			formatAction={async () => {
 				if (activeModuleTab === null) {