Add codespell support with configuration and fixes

[yarikoptic]

Add codespell configuration and fix existing typos. This is a reincarnated

• chore: add codespell support (config, workflow to detect/not fix) and make it fix some typos #546

which was closed due to rot (conflicts) etc.

More about codespell: https://github.com/codespell-project/codespell

I personally introduced it to dozens if not hundreds of projects already and so far only positive feedback.

CI workflow has 'permissions' set only to 'read' so also should be safe.

Changes

Configuration & Infrastructure

• Added .codespellrc with skip patterns for SVG, lock files, CSS, cache dirs
• Created GitHub Actions workflow to check spelling on push to main and PRs
• Added ignore-regex for camelCase/PascalCase identifiers (e.g., doubleClick)
• Added ignore-words-list for domain terms: ser (biology: serine), cyclin (biology: protein)

Ambiguous Typos Fixed Manually (2 fixes)

• custome -> custom (samples/client/angular/README.md) - "Google Map custom components"
• Reenable -> Re-enable (tools/editor/middleware/gemini.ts) - TODO comment

Non-Ambiguous Typos Fixed with codespell -w (3 fixes)

• releative -> relative (input-area.scss)
• reponse -> response (chat-service.ts)
• effecient -> efficient (a2ui_protocol.md)

All typo fixes are in comments/docs - no functional code changes.

Testing

Codespell passes with zero errors after all fixes.

---

🤖 Generated with Claude Code and love to typos free code

[google-cla]

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[gemini-code-assist]

Code Review

This pull request introduces codespell to automate typo detection, a valuable addition for maintaining code quality. The changes include the necessary configuration and fixes for several existing typos. My review focuses on enhancing the .codespellrc configuration to improve its effectiveness. I've suggested expanding the list of skipped directories to prevent noise from dependencies and build artifacts, and refining the regular expression for ignoring identifiers to better handle various coding styles like PascalCase with acronyms.

[gemini-code-assist]

It's a good practice to also exclude common build output and dependency directories from spell checking. Consider adding node_modules, build, and dist to the skip list to avoid spell-checking third-party code and generated files.

skip = .git*,*.svg,package-lock.json,*-lock.yaml,*.lock,*.css,.codespellrc,.cache,.npm,node_modules,build,dist

[gemini-code-assist]

The current regex for ignoring PascalCase identifiers (\b[A-Z][a-z]+[A-Z]\w*\b) is a bit strict and might not cover cases with acronyms (e.g., URLHandler) or consecutive capital letters. A slightly broader but still safe regex could be \b[A-Z]\w*[A-Z]\w*\b, which ignores any word starting with a capital letter and containing at least one other capital letter. This would cover more identifier patterns while still avoiding common English words.

ignore-regex = ^\s*"image/\S+": ".*|\b[a-z]+[A-Z]\w*\b|\b[A-Z]\w*[A-Z]\w*\b

[yarikoptic]

not too bad AI! but I would say we can enter those waters when run into them

[yarikoptic]

as for CLA check:

❌ e247fd1 Co-Author: <noy​@anthropic.com>❌ e247fd1 Co-Author: <noy​@anthropic.com>

as I annotate claude code assisted commits with

Co-Authored-By: Claude Code 2.1.63 / Claude Opus 4.6 <noreply@anthropic.com>

what would you expect me to do

• drop that annotation?
• CLA on that beast's behalf?
• nevermind