[Improvement] Spell check only PR-changed files and added manual dispatch for full check

[richarddushime]

Description

This improves the spell check feature and Instead of commenting on every Pull Request , typos from other files

• PR triggers now only spell-check files changed in the PR (not entire site contents)
• Added workflow_dispatch with option to check all content manually
• Updated script to handle both modes with appropriate output messages

Type of Change

• New feature

Testing

• Tested locally
• Previewed on staging.forrt.org
• Not tested yet

Checklist

• Self-reviewed my changes
• Verified links and formatting are correct
• No new warnings or errors

Notes

[github-actions]

👍 All image files/references (if any) are in webp format, in line with our policy.

[github-actions]

✅ Spell Check Passed

No spelling issues found when checking 2 changed file(s)! 🎉

[LukasWallrich]

✅ Staging Deployment Status

This PR has been successfully deployed to staging as part of an aggregated deployment.

Deployed at: 2026-03-12 20:21:34 UTC
Staging URL: https://staging.forrt.org

The staging site shows the combined state of all compatible open PRs.

[Copilot]

Pull request overview

Updates the repository’s spell-check automation to support two execution modes (PR-only vs full scan), aiming to reduce CI work on pull requests while still enabling an on-demand full repository check.

Changes:

• Add PR mode to check_spelling.py that spell-checks only PR-changed files (via CHANGED_FILES) and keep a full-scan mode (via CHECK_ALL).
• Extend the GitHub Actions workflow to compute changed files for PRs and add workflow_dispatch for manual full checks.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
scripts/spell_check/check_spelling.py	Adds mode selection logic (PR-only vs full) and adjusts comment formatting to reflect the mode/files checked.
.github/workflows/spell-check.yaml	Adds workflow_dispatch, computes changed files in PR runs, and passes mode-related env vars into the script.

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[github-actions]

✅ Spell Check Passed

No spelling issues found when checking 2 changed file(s)! 🎉