Dogfood variable glyph editing flow

[kostyafarber]

Summary

• Adds app-shell to renderer command routing and a Glyph menu action for reversing the selected contour.
• Makes renderer clipboard access async through preload/main IPC and updates keyboard routing to await copy, cut, and paste.
• Keeps the renderer workspace alive across Fast Refresh by splitting context objects from providers and exposing window.shift from a stable runtime.
• Adds lazy source-layer materialization for the opened glyph, backed by a native cloneGlyphLayer intent with fresh internal IDs.
• Adds shift-cli inspect --view layers and layer counts in inspect JSON for debugging .shift packages.

Validation

• cargo fmt
• pnpm format:check
• pnpm typecheck
• pnpm lint:check
• cargo test -p shift-bridge -p shift-font -p shift-cli
• pnpm --filter @shift/desktop test src/renderer/src/lib/editor/Editor.test.ts src/renderer/src/lib/clipboard/Clipboard.test.ts src/renderer/src/lib/keyboard/KeyboardRouter.test.ts
• pre-commit hook: cargo check/fmt/clippy/test, oxfmt, oxlint, tsgo typecheck, deadcode, vitest

[kostyafarber]

should this be private?