feat: add WhatsApp auth retry

[don7panic]

Type of Change

• enhancement - adds WhatsApp auth retry logic

Description

Added automatic reconnection handling for WhatsApp authentication:

{"level":50,"time":1770087396028,"pid":3709,"hostname":"Joe-Air.local","fullErrorNode":{"tag":"stream:error","attrs":{"code":"515"}},"msg":"stream errored out”}

• Implements retry mechanism with configurable max attempts, default: 5.
• Special handling for stream error (515) with detailed logging.

[TomGranot]

@gavrielc Tom just finished a comprehensive Baileys deep-dive and wrote 38 WhatsApp connector tests (PR #182). Given that audit work, we think this PR's retry logic for 515 (restartRequired) disconnects is solid and worth merging — it handles a real reliability issue where WhatsApp servers periodically request client restarts. The diff is clean and only touches src/whatsapp-auth.ts. Recommending merge.

[Andy-NanoClaw-AI]

Hey @don7panic 👋 Thanks for this fix — WhatsApp auth reliability is critical!

This was superseded by #443 (merged), which fixed connection issues by switching to fetchLatestWaWebVersion(), covering the same auth reliability problem with a more complete solution. This PR also has merge conflicts with the current codebase.

We're adding Status: Pending Closure. Thanks for the contribution! 🙌

[Andy-NanoClaw-AI]

Update: Apologies for the previous comment — I incorrectly flagged this as superseded by #443. After reviewing more carefully, #443 fixed a different issue (405 connection failure via fetchLatestWaWebVersion()), while this PR specifically handles stream error 515 (WhatsApp restartRequired disconnects) with retry logic. These are distinct reliability concerns.

Removing the Status: Pending Closure label. Tom's recommendation from Feb 12 stands — this is worth a proper review. @gabi-simons tagging you as requested.