fix(import): auto-detect JSON format and show readable errors (#1) (#3296)

* fix(import): auto-detect JSON format and show readable errors (#1)

Readable import errors, a fail-soft v4 parser, and auto-detect of the JSON format so uploads just work. The format dropdown becomes an optional override. PDF and DOCX (AI) paths are untouched.

* fix(import): address review feedback on the v4 guard and error message

- reactive-resume-v4-json.tsx: reject arrays in isRecord so array-valued
  basics, sections, or metadata no longer pass the v4 shape guard.
- reactive-resume-v4-json.tsx: reuse the guard's error instance in the
  catch arm instead of allocating a duplicate NOT_V4_MESSAGE.
- error.ts: use a singular "Problem" label for root-level Zod issues so
  the message stays grammatical.
- add a regression test for array-valued v4 branches.

* fix(import): preserve selected JSON format

* test(import): cover selected JSON parser

---------

Co-authored-by: MrTig-afk <MrTig-afk@users.noreply.github.com>
Co-authored-by: Amruth Pillai <im.amruth@gmail.com>

apps/web/src/dialogs/resume/parse-json.test.ts

@@ -0,0 +1,8 @@
+import { describe, expect, it } from "vitest";
+import { parseResumeJson } from "./parse-json";
+
+describe("parseResumeJson", () => {
+	it("keeps a selected v4 import from falling back to JSON Resume", () => {
+		expect(() => parseResumeJson("{}", "reactive-resume-v4-json")).toThrow(/v4/i);
+	});
+});