refactor: split config module

src/config/legacy-migrate.ts

@@ -0,0 +1,19 @@
+import { applyLegacyMigrations } from "./legacy.js";
+import type { ClawdisConfig } from "./types.js";
+import { validateConfigObject } from "./validation.js";
+
+export function migrateLegacyConfig(raw: unknown): {
+  config: ClawdisConfig | null;
+  changes: string[];
+} {
+  const { next, changes } = applyLegacyMigrations(raw);
+  if (!next) return { config: null, changes: [] };
+  const validated = validateConfigObject(next);
+  if (!validated.ok) {
+    changes.push(
+      "Migration applied, but config still invalid; fix remaining issues manually.",
+    );
+    return { config: null, changes };
+  }
+  return { config: validated.config, changes };
+}