Fix undefined matrix variables in CodeQL workflow

[Copilot]

The CodeQL workflow referenced matrix.language and matrix.build-mode throughout but never defined them in the matrix configuration, causing the workflow to fail or skip steps.

Changes:

• Added language: javascript-typescript and build-mode: none to matrix.include
• Added inline comment explaining the configuration for this HTML/JavaScript project

Affected references:

# Job name, runner selection, init action, conditional steps, and analysis categorization
name: Analyze (${{ matrix.language }})
runs-on: ${{ (matrix.language == 'swift' && 'macos-latest') || 'ubuntu-latest' }}
languages: ${{ matrix.language }}
build-mode: ${{ matrix.build-mode }}
if: matrix.build-mode == 'manual'
category: "/language:${{matrix.language}}"

All six references now resolve to defined values.

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