Settings: terminal font size (S/M/L)

[burakgon]

Why: The terminal is fixed at one font size. On a phone some people want denser output; on a desktop monitor some want it bigger. A simple S / M / L choice in Settings would cover both.

Where:

• packages/web/src/settings/SettingsPanel.tsx — add a "Terminal font size" control (three buttons or a <select>: Small 12 / Medium 14 / Large 16).
• packages/web/src/pwa/theme.ts or a new tiny module — persist the choice in localStorage under roamcode.termfont (follow the pattern of roamcode.theme in theme.ts: load with a validated fallback).
• packages/web/src/chat/TerminalView.tsx — read the stored value when constructing the xterm Terminal({ fontSize }), and call term.options.fontSize = n + refit when it changes (listen the same way theme changes are handled).

Acceptance criteria:

• New sessions open with the chosen size; changing it applies to open terminals without a reload.
• Choice survives a page reload (localStorage).
• Default stays exactly as today (Medium/14) for existing users.
• pnpm typecheck && pnpm -C packages/web test pass; add a small test following packages/web/src/pwa/theme.test.ts.

Hints: grep for fontSize in TerminalView.tsx to find the xterm construction; the Settings panel already has grouped controls you can copy the markup from.

[adityabhatkar23]

i would like to work on this issue can you assign this to me

[burakgon]

Thanks for volunteering — I’ve assigned this to you. Please follow the acceptance criteria in the issue, especially applying changes to already-open terminals without a reload, preserving Medium/14 as the default, and adding focused persistence/fallback tests.

Please open a focused PR with Closes #66 when it is ready. If you get blocked or can no longer work on it, leave a note here so we can make it available again.