fix(migrate-ts): make CHECK-expr cast-strip quote-aware (preserve :: in regex patterns)

The cast-strip introduced for the IN/ANY fold was quote-unaware, so a regex
pattern containing '::' (e.g. 'a::foo') normalized to 'a' — making two distinct
regex CHECKs compare equal and a pattern change silently missed. Restrict the
strip to a cast that follows a CLOSING quote (PG's 'open'::text form) via a
lookbehind; a '::' inside a quoted pattern is preserved.

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

Author: dmealing

server/typescript/packages/migrate-ts/src/check-expr-compare.ts

@@ -16,7 +16,12 @@
 export function normalizeCheckExpr(expr: string): string {
   const stripped = expr
     .toLowerCase()
-    .replace(/::\s*"?\w+"?/g, "") // drop `::text` / `::"MyType"` type casts PG adds to literals
+    // Drop `::text` / `::"MyType"` type casts PG adds to literals. The lookbehind
+    // restricts the strip to a cast that immediately follows a CLOSING single
+    // quote (`'open'::text`), so a `::` appearing INSIDE a regex pattern literal
+    // (`slug ~ 'a::foo'`) is preserved — otherwise two distinct regex CHECKs would
+    // normalize equal and a pattern change would be silently missed.
+    .replace(/(?<=')::\s*"?\w+"?/g, "")
     .replace(/[()[\]]/g, " ")     // drop parens AND square brackets (ARRAY[…])
     .replace(/\s+/g, " ")
     .trim();

server/typescript/packages/migrate-ts/test/check-evolution/normalize.test.ts

@@ -27,6 +27,14 @@ describe("normalizeCheckExpr", () => {
       "status = ANY (ARRAY['OPEN'::text, 'CLOSED'::text, 'CANCELLED'::text])",
     )).toBe(false);
   });
+  test("a `::` inside a regex pattern is preserved (only post-quote casts are stripped)", () => {
+    // the cast-strip must not corrupt a regex literal containing `::`, else two
+    // distinct regex CHECKs would compare equal and a pattern change be missed.
+    expect(checkExprEquals("slug ~ 'a::foo'", "slug ~ 'a::bar'")).toBe(false);
+    expect(normalizeCheckExpr("slug ~ 'a::foo'")).toBe("slug ~ 'a::foo'");
+    // but PG's post-literal `::text` cast (enum form) is still stripped
+    expect(normalizeCheckExpr("'open'::text")).toBe("'open'");
+  });
   test("genuinely different expressions are not equal", () => {
     expect(checkExprEquals("col >= 0", "col >= 5")).toBe(false);
   });