fix: #927 — jwt.verify dispatches per algorithm (ES256/RS256), accepts private PEM

[proggeramlug]

Summary

The previous #927 fix (#936) made jwt.verify return the parsed claims object instead of the JSON text, but ES256 / RS256 tokens were still failing verification silently — the generic NativeModSig table routed every algorithm through js_jwt_verify, which was hardcoded to HS256. The token was signed correctly with ES256, then Validation::new(Algorithm::HS256) rejected it with InvalidAlgorithm, the runtime returned a null pointer, and js_json_parse_or_null surfaced it as null — breaking shop-admin's auth middleware on the very first authenticated request after a successful signup.

Fix mirrors the sign side's algorithm-aware dispatch:

• Add js_jwt_verify_es256 / js_jwt_verify_rs256 runtime functions in perry-stdlib/src/jsonwebtoken.rs. Both auto-derive the public key from a private PEM (PKCS#8 or SEC1 for EC, PKCS#8 or PKCS#1 for RSA) so callers can reuse the same PEM they passed to sign — matches Node jsonwebtoken's ergonomics. Direct public-key PEMs (SPKI) also accepted unchanged.
• Replace the generic NativeModSig verify row with lower_jsonwebtoken_verify in crates/perry-codegen/src/lower_call/native.rs. Routes on the canonical algorithms: ['…'] array option as well as the singular algorithm: '…'. Falls back to HS256 when the option is absent or unparseable. Return path still pipes through js_json_parse_or_null so user code sees an object on success and null on failure (same contract as before).
• Bonus: js_jwt_sign_es256 now also accepts SEC1 (-----BEGIN EC PRIVATE KEY-----) PEMs, which is what openssl ecparam -genkey -name prime256v1 emits by default. Symmetric with the new verify ergonomics.

New perry-stdlib deps gated on bundled-jsonwebtoken: p256 (EC public-key derivation), rsa (RSA public-key derivation), spki (PEM serialization helpers).

Test plan

• Standalone repro (sign + verify a token with algorithms: ['ES256']) now returns the parsed claims object — typeof decoded is "object", decoded.sub accessible. Previously returned null.
• Same repro with SEC1 EC private PEM (openssl default) now signs + verifies — previously failed with InvalidKeyFormat.
• HS256 path still works (existing perry#924 regression tests untouched).
• Full shop-admin signup → first authenticated route — re-running to confirm the perry#665 → Native route returns body 0 + HTTP 200 after sequence of @perryts/mysql writes; first INSERT commits, rest silently no-op, explicit return dropped #748 → Closure-captured numeric params read as 0 inside object-literal : Date method (@perryts/mysql MyDateTime.toDate shape) #858 → Native shop-admin signup SIGBUS in toUser → dtRequiredToIso (downstream of @perryts/mysql MyDateTime.toDate corruption) #859 → Native server SIGSEGV at jwt.sign(...) (jsonwebtoken) after resumed async-step body — follow-up to #859 #915 → jwt.verify returns JSON-stringified payload (string) instead of parsed object — auth middleware breaks #927 → throw new Error(...) in async Fastify route handler crashes process (exit 1) instead of being caught by setErrorHandler #928 cascade is finally complete end-to-end.

Repro

import jwt from "jsonwebtoken";
import { readFileSync } from "fs";
const PEM = readFileSync("/tmp/skelpo-jwt.pem", "utf8");
const TOK = jwt.sign({ sub: "u-001", acc: "a-001" }, PEM, { algorithm: "ES256", issuer: "z" });
const decoded = jwt.verify(TOK, PEM, { algorithms: ["ES256"], issuer: "z" }) as any;
console.log("typeof:", typeof decoded, "sub:", decoded?.sub);

Before this PR: typeof: object sub: undefined (decoded was null).
After: typeof: object sub: u-001.