fix(desktop): bundle Plus Jakarta + JetBrains Mono locally (no Google Fonts CDN)

[hqhq1025]

Summary

Removes the three <link rel="preconnect|stylesheet"> tags pointing at fonts.googleapis.com / fonts.gstatic.com from apps/desktop/src/renderer/index.html. The renderer already loads Geist + Fraunces + JetBrains Mono locally via @fontsource-variable/* through @open-codesign/ui/fonts (wired from apps/desktop/src/renderer/src/main.tsx:2), so these CDN links were both redundant and a hard-constraint violation.

Why this matters

1. BYOK / no-telemetry violation (hard constraint feat(desktop): settings + theme + command palette + better preview states #3). Every cold start was firing two preconnects and a stylesheet GET to Google before the app even rendered — i.e., a third-party network ping by default, no opt-in. CLAUDE.md is explicit: "no telemetry by default."
2. Offline launch was broken. This is an Electron desktop app; users on planes / behind firewalls / on captive networks would hang on the blocking <link rel="stylesheet"> until the request timed out, then render with the system fallback.
3. Multi-second FOUC. display=swap meant first paint used system-ui, then re-flowed once the CDN font landed — visible flash on every launch.
4. China / corp-network reliability. fonts.googleapis.com is unreachable from many networks; users in those regions were getting permanent fallback rendering with no indication why.

What I changed (and didn't change)

• apps/desktop/src/renderer/index.html — removed lines 8–13 (the 3 Google Fonts links). One file, six lines deleted.
• I did not add @fontsource-variable/plus-jakarta-sans to packages/ui as the audit suggested. After the feat(ui): Anthropic-inspired warm aesthetic refresh (commit 269658d), --font-sans resolves to "Geist Variable" and --font-display to "Fraunces Variable" (see packages/ui/src/tokens.css:56-58). The Plus+Jakarta+Sans family the CDN was loading is not referenced by any token or component — it was dead weight from a pre-refresh era. Adding the fontsource package would have shipped ~120KB of woff2 nobody renders.
• JetBrains Mono is already bundled via @fontsource-variable/jetbrains-mono in packages/ui/src/fonts.ts:7, so the CDN's mono load was also redundant.

Verification

• pnpm typecheck — pass (10/10 turbo tasks)
• pnpm lint — only pre-existing warnings, no new findings
• pnpm build (electron-builder) — exit 0; ignored hdiutil cleanup quirks are unrelated to this change
• pnpm test (pre-commit hook) — 138/138 desktop, all packages green
• Built apps/desktop/out/renderer/index.html — grep for fonts.googleapis|fonts.gstatic returns 0 matches
• Built assets/ directory contains all expected woff2 subsets (geist-, fraunces-, jetbrains-mono-*)
• Install-size delta: net −6 lines of HTML, no new deps. Bundle size strictly decreases.

Test plan

• Launch app with network disabled — should render brand fonts immediately, no fallback flash
• DevTools Network tab on cold start — zero requests to fonts.googleapis.com / fonts.gstatic.com
• Visual regression on Welcome / TopBar / Wordmark — Geist + Fraunces + JetBrains Mono unchanged

Principles checklist

• ✅ Compatibility — no API/IPC changes, schema-version untouched
• ✅ Upgradeability — fewer external dependencies → easier
• ✅ No bloat — removes weight, adds none
• ✅ Elegance — fewer moving parts, tokens are now the single source of truth for typography

[github-actions]

Findings

• No high-confidence issues found in added/modified lines.

Summary

• Review mode: initial
• No issues identified in this diff. Residual risk: visual regression is still possible if local font-face assets are not present at runtime (not verifiable from this diff alone).
• open-codesign Bot

Testing

• Not run (automation)