The create and edit over-cap fixtures were numeric literals, so raising the cap to 500000 left the edit test sending under-cap content until 3cdbafa bumped the literal. The cap is now the exported constant posts.MaxContentLength, enforced once by the shared validator, and both fixtures are MaxContentLength+1. Changes: - Export MaxContentLength (500000 bytes, the postv2 lexicon's maxLength) - normalizeAndValidatePostContent uses it; value and error text unchanged - Create and update validation tests send MaxContentLength+1 Closes 2026-09-09-posts-update-cap-test-stale-after-50k-raise. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>