Add Vox — hands-free voice canvas extension 🤖🤖🤖

[aasis21]

Add Vox — hands-free voice canvas extension

Vox gives any GitHub Copilot session a voice: speak your turn and hear the agent's reply read back, with a reactive listening orb. Voice in, voice out — no editor, no tab-juggling.

• Repo: https://github.com/aasis21/vox (public, MIT)
• Site + demo: https://aasis21.github.io/vox
• Type: external canvas extension (uses createCanvas / joinSession from @github/copilot-sdk/extension), so it renders inline in the Copilot app and runs in the CLI.

What this PR does

Adds a single external entry, following the existing Coffilot precedent — Vox stays hosted in its own repo. No in-repo runtime code is added.

• extensions/external.json → new vox entry (author, keywords, screenshots, installUrl/sourceUrl → aasis21/vox)
• extensions/external-assets/vox-preview.png → preview image

Included CI fix (why this PR touches .github/workflows/)

This PR also carries a one-line fix to .github/workflows/validate-canvas-extensions.yml, because the external route is currently broken by a very recent regression:

• Add canvas schema validation to extension submission workflow #2161 (merged only hours before this PR, 2026-07-01) rewrote the validator into a bash loop that reduces each changed path under extensions/ to its first segment, then checks it against a directory-name allowlist ^[a-z0-9][a-z0-9-]*$.
• For a changed file like extensions/external.json, that first segment is external.json — which fails the allowlist on its dot and errors with "invalid extension directory name." The loop skips the external-assets/ folder but not the external.json file.
• The bug is latent: Add canvas schema validation to extension submission workflow #2161 itself didn't modify extensions/external.json, so its own run took the "No canvas extension directories changed — skipping" branch and went green. It only fires when a PR actually edits external.json — and this is the first such PR since Add canvas schema validation to extension submission workflow #2161. (Coffilot predates the check entirely: external.json was created back in Add canvas previews, external extension links, and release notes showcase #1987 on 2026-06-16, before the strict validator existed.)

The fix skips any top-level catalog file (identified by a dot in the name), mirroring the same heuristic already applied to the local validator in #2029. Real extension directories (lowercase alnum + hyphens, no dot) validate unchanged. Happy to split this into a standalone PR if you'd prefer.

Notes for maintainers

• Vox fits the "Accessibility and inclusive design" category in CONTRIBUTING — it's a hands-free voice UI, not generic model-duplicating guidance.
• Canvas extensions aren't yet covered in CONTRIBUTING.md or an issue template, so I mirrored the external.json shape used for Coffilot. Happy to adjust to whatever intake you prefer.
• npm start was run; it produced no README.md or marketplace.json diff (external.json feeds website data only), so this stays minimal.

🤖 This PR was prepared with AI assistance.

[Copilot]

Pull request overview

Adds Vox as an external Copilot canvas extension entry so it can be surfaced by the repository’s extensions/website data pipeline, with a bundled preview image asset.

Changes:

• Added a new vox entry to extensions/external.json with metadata (author, keywords, screenshots, install/source URLs).
• Added extensions/external-assets/vox-preview.png and wired it up as the icon/gallery image for the new entry.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
extensions/external.json	Registers the new external extension listing and points to the preview image asset.
extensions/external-assets/vox-preview.png	Adds the preview image referenced by the new external listing.

[aasis21]

Heads-up for reviewers: this PR includes a small, self-contained CI fix in addition to the Vox catalog entry.

Why the workflow change is here: registering an external extension via extensions/external.json (the documented external route, e.g. coffilot) was failing the Validate Canvas Extensions workflow. The step reduces each changed path under extensions/ to its first segment, so extensions/external.json becomes ext_name=external.json. Only external-assets/ was skipped, so external.json fell through to the directory-name allowlist and failed on its dot — blocking every external-extension PR.

The fix skips top-level catalog files (identified by a dot in the name), mirroring the same fix already applied to the local validator in #2029. Real extension directories (lowercase alnum + hyphens, no dot) still validate unchanged.

Happy to split this into a separate PR if you'd prefer — it's just required for this contribution (and any external one) to go green.