chore(test): use RequestCatcher webhook URLs in integration tests

[FranDisalvo90]

Problem

The daily scheduled Build & Test run has been failing since ~2026-06-01. ~10 integration test classes fail in setUp with:

java.lang.Error: Create item request responded with error, code=400,
message='Webhook url is a reserved placeholder and cannot be used'

Root cause

This is an API-side change, not a repo regression: the last green scheduled run (May 31) and the first red one (Jun 1) ran the same master with no code change in between (runtime dropped from ~6min to ~1.5min because the tests now abort early in setUp).

Around Jun 1 the API started rejecting reserved/placeholder webhook URLs. The tests hardcoded such URLs:

• helper/ItemHelper.java → https://webhookUrl.pluggy.ai (used by createPluggyBankItem, so it broke the setUp of almost every item-dependent test)
• CreateItemTest / UpdateItemTest → https://www.test.com / https://www.test2.com (no longer accepted either)

Tests that don't create items (connectors, categories, auth, connect token) keep passing.

Fix

Replace the hardcoded placeholders with public, reachable HTTPS RequestCatcher endpoints, as recommended by the Pluggy webhook docs for testing. Distinct paths are used where the assertions compare URLs (UpdateItemTest). The negative http://www.test.com case (which tests rejection of non-HTTPS) is left untouched.

Validation

• ✅ mvn test-compile (JDK 11)
• ⏳ Integration tests run against the live API with Doppler credentials in CI — this PR's Build & Test run will confirm the fix.

🤖 Generated with Claude Code

[FranDisalvo90]

Consolidado en #79: el commit del fix de los integration tests (RequestCatcher webhook URLs) se movió a la branch feat/account-reserved-balance. Cierro este PR en favor de #79.