feat: runtime font-size zoom via Ctrl/Cmd +/-/0

[jesse23]

Summary

• Add in-session font-size zoom via Ctrl/Cmd + =/-/0, matching VS Code and native terminal conventions
• Uses term.options.fontSize (xterm.js options-proxy pattern) to trigger ghostty-web's internal renderer update
• Fix key leak: add stopPropagation() so zoom keys are not forwarded to the PTY as literal characters

Changes

• src/client/index.ts — attach window capture-phase keydown handler for zoom; preventDefault() stops browser page-zoom, stopPropagation() stops ghostty-web from forwarding the key to the PTY
• docs/adrs/023.client.font-size-zoom.md — ADR documenting the decision

Related ADRs

• ADR 023 — this feature
• ADR 022 — fit() is called after each zoom step to recentre the canvas

[Copilot]

Pull request overview

Adds a client-side, in-session font-size zoom feature (Ctrl/Cmd + = / - / 0) to adjust the Ghostty terminal’s fontSize at runtime, while preventing those keystrokes from being forwarded to the PTY. Includes an ADR documenting the approach and tradeoffs.

Changes:

• Add a capture-phase window keydown handler to implement zoom-in / zoom-out / reset and call fit() after each step.
• Stop zoom shortcut keystrokes from leaking to the PTY via stopPropagation().
• Add ADR 023 documenting the decision and rationale.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
src/client/index.ts	Implements runtime font zoom via term.options.fontSize and global key interception.
docs/adrs/023.client.font-size-zoom.md	Documents the decision, constraints, and rationale for the chosen implementation.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.