[CompleteDotTech]

Recognize => as a single lexical token before the fallback. This prevents import/call-like text inside an arrow-return regular expression from becoming source candidates. Carries the related Sharp Copilot finding across the bundled lexer copies; no runtime claims or code execution.

Validation: 31 local tests passed, regression and checksum included; git diff --check passed. Require Copilot review and exact-head CI before merge.

[Copilot]

🟢 Approval recommended

The focused lexer correction has a targeted regression test and no identified blocking issues; exact-head CI remains required before merge.

No open issues 🎉

What changed in this PR

This PR fixes the offline source checker's lexer so regular expressions returned by arrow functions remain opaque rather than producing false source candidates.

Changes:

• Recognizes => as a single token, enabling existing regex handling.
• Adds a regression test for import- and constructor-like text inside an arrow-return regex.
• Updates the checker’s checksum.

File	Description
vm2_nesting_check.py	Tokenizes arrow operators before the fallback.
test_source.py	Verifies arrow-return regex contents produce no source candidates.
SHA256SUMS	Refreshes the checker’s SHA-256 checksum.

_{Review effort: Balanced}