fix(repl): Dot commands not working.

[gluzandii]

This Pull Request fixes/closes #5219.

This commit fixes the parsing error that shows when using dot commands in the REPL.
It fixes this by preventing the passing of the dot commands to the JS parser.

It changes the following:

• cli/helper.rs: Prevents passing of dot commands to JS parser.

[Copilot]

Pull request overview

This PR updates the CLI REPL input validator to avoid running the JavaScript parser on REPL “dot commands”, preventing a syntax error from being displayed when using commands like .help.

Changes:

• Treat inputs starting with . as valid in the rustyline validator so dot commands don’t trigger JS parsing errors.

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[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	52,963	52,963	0
Passed	50,545	50,545	0
Ignored	1,426	1,426	0
Failed	992	992	0
Panics	2	2	0
Conformance	95.43%	95.43%	0.00%

Tested main commit: 66a1cd268ce6006918032b5d0f98d3a63c81b188
Tested PR commit: be66525a1cb0f031befd26e72e33c6a6b4cf3722
Compare commits: 66a1cd2...be66525

[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 59.79%. Comparing base (6ddc2b4) to head (be66525).
⚠️ Report is 916 commits behind head on main.

Files with missing lines	Patch %	Lines
cli/src/helper.rs	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #5231       +/-   ##
===========================================
+ Coverage   47.24%   59.79%   +12.55%     
===========================================
  Files         476      582      +106     
  Lines       46892    63462    +16570     
===========================================
+ Hits        22154    37948    +15794     
- Misses      24738    25514      +776     

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