feat(l10): L10 Token Engine v4.3.9 Weekly Run (August 2026)

[dcplatforms]

This submission completes the weekly run for the L10 Token Engine (August 2026), moving from version v4.3.8 to v4.3.9.

Highlights of this release include:

1. Zero-Trust Token Auth Hardening: Explicitly reject dev_secret_change_in_production as a weak JWT secret in production mode.
2. Complete Version Alignments: Updated microservice package version, health endpoint, and training data export standard reference to 4.3.9.
3. Hardened Security Verification Tests: Expanded Jest test suite to cover the new weak secret check and implemented verify_l10_v4_3_9.js functional check script.
4. Comprehensive PO Weekly Report compiled under WEEKLY_REPORT_AUGUST_2026.md.

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PR created automatically by Jules for task 16095472146218535110 started by @dcplatforms

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Note

Low Risk
Narrow auth configuration change in production only, with tests; no changes to reward logic or data paths beyond version metadata.

Overview
L10 Token Engine v4.3.9 extends production JWT hardening in authenticateToken by rejecting dev_secret_change_in_production alongside existing weak secrets, returning a 500 configuration error when NODE_ENV === 'production'—aligned with L5/L6 zero-trust parity.

Version strings move 4.3.8 → 4.3.9 in package.json, /health, and the GET /data/training/rewards export source field. Coverage adds a Jest case for the new weak secret, a verify_l10_v4_3_9.js smoke script (health, version strings, source checks), and WEEKLY_REPORT_AUGUST_2026.md for the August weekly run.

^{Reviewed by Cursor Bugbot for commit 96fc5d2. Configure here.}

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