feat(web): add Basic language support in file viewer

[brendan-kellam]

Summary

• Maps .bas extension to BASIC language in language detection
• Adds basic CodeMirror language using the VB stream language parser
• Enables syntax highlighting for Basic files in the file viewer

Test plan

• Open a .bas file in the file viewer and verify syntax highlighting renders correctly
• Verify the BASIC language icon appears correctly

Summary by CodeRabbit

New Features

• Introduced BASIC language syntax highlighting support in the file viewer for improved code readability.
• Implemented automatic detection of .bas file extensions to ensure proper language identification and syntax highlighting.

[coderabbitai]

Walkthrough

This pull request adds support for BASIC language syntax highlighting in the file viewer. It introduces CodeMirror language definition mapping, file extension detection override for .bas files, and updates language metadata to enable highlighting for BASIC code files.

Changes

Cohort / File(s)	Summary
Documentation CHANGELOG.md	Added entry documenting the introduction of basic language syntax highlighting feature.
Language Support Configuration packages/web/src/lib/codemirrorLanguage.ts, packages/web/src/lib/languageMetadata.ts	Added CodeMirror language mapping for "basic" using legacy VB mode and updated BASIC language metadata to reference the new CodeMirror language definition.
File Extension Detection packages/web/src/lib/languageDetection.ts	Extended ambiguous extension overrides to map .bas file extension to BASIC language.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• PR #1026: Introduced ambiguousExtensionOverrides mechanism for language detection, which this PR builds upon by adding the .bas→BASIC mapping.

Suggested reviewers

• msukkari

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: adding Basic language syntax highlighting support to the web file viewer.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch brendan-kellam/basic-language-support

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@CHANGELOG.md`:
- Line 12: The CHANGELOG entry uses "Basic" but the codebase uses the all-caps
key "BASIC"; update the CHANGELOG line to use "BASIC" (matching
languageMetadataMap["BASIC"] and ambiguousExtensionOverrides) so the wording is
consistent with the repository's language identifiers and documentation.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 833f52d3-528c-4433-900c-2015524479b1

📥 Commits

Reviewing files that changed from the base of the PR and between 5fc21fd and be0a813.

📒 Files selected for processing (4)

• CHANGELOG.md
• packages/web/src/lib/codemirrorLanguage.ts
• packages/web/src/lib/languageDetection.ts
• packages/web/src/lib/languageMetadata.ts