Generate remaining sig help tests, fix remaining bugs

[jakebailey]

• Properly handle the active parameter capability
• Don't set active parameter when client allows it
• Check inComment now that we have it
• Port over backup JS sig help code

Plus, generate all remaining tests that mention sig help. Some new tests with unrelated issues (other LSP features) become skipped.

Fixes #1495

[Copilot]

Pull request overview

This PR improves signature help functionality by properly handling the active parameter capability, ensuring that activeParameter is placed on SignatureInformation when the client supports it rather than on the top-level SignatureHelp. It also adds comment-in-code checking, ports backup JavaScript signature help code, and generates all remaining signature help tests.

Key Changes:

• Moved activeParameter from SignatureHelp to SignatureInformation based on client capabilities
• Added inComment checking to bail out early when user triggers signature help in comments
• Implemented JavaScript fallback signature help for untyped code
• Generated comprehensive signature help test suite

Reviewed changes

Copilot reviewed 145 out of 145 changed files in this pull request and generated no comments.

File	Description
internal/ls/signaturehelp.go	Core implementation of capability-aware active parameter handling and JS fallback
Test baseline files (multiple)	Updated baselines reflecting new active parameter placement
Generated test files (multiple)	New comprehensive test coverage for signature help scenarios

[DanielRosenwasser]

Why is this one a manual test?

[jakebailey]

This is a JS test that previously used removed JSDoc syntax, like function(string, boolean=). The two manual tests are ones I fixed.

[DanielRosenwasser]

I hate when my unions of dissimilar tyes don't haveGoodDisplay

[DanielRosenwasser]

This one is just type-ordering, right?

[jakebailey]

Yep, but we loved tests with hardcoded strings (for better or for worse).