Update Stylus common-issues troubleshooting

[anegg0]

Description

Part of a section-wide Stylus documentation update that brings docs/stylus/ back in line with the current stack (stylus-sdk 0.10.7 / cargo-stylus 0.10.7 / Nitro v3.11.0). The update is split into ~25 small, independently reviewable PRs (all tagged stylus).

This PR: replaces the non-existent ensure! macro and --wasm-opt flag and fixes a TestVM setter.

Code examples were verified against the live toolchain — compiled, and deployed on a local Nitro dev node where applicable — and conceptual claims were checked against the Nitro source. The branch builds clean with yarn build (strict onBrokenLinks).

Document type

• Troubleshooting

Checklist

• My changes follow the style conventions outlined in CONTRIBUTE.md
• I have used sentence-case for titles and headers
• I have used descriptive link text
• I have checked for broken links
• I have verified that my changes don't break the build (yarn build)

Additional Notes

Version strings appear here as literals; they are centralized into src/resources/globalVars.js in a final follow-up PR. Companion PRs share the stylus tag.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
arbitrum-docs	Ready	Preview	Jun 24, 2026 8:23pm

[anegg0]

Consolidated into the clustered Stylus docs PRs (tagged stylus): #3407–#3413, plus #3405 and #3406. Closing this granular PR in favor of the section-level cluster.