* perf(typecheck): pnpm tc uses the pinned Bun checker when available
bun check (Bun 1.4.3, TypeScript 7.0.2 parity, already used by CI) checks the
node project in ~29 CPU-s / ~2 GB peak vs tsc's ~98 CPU-s / ~16.6 GB. tsc's
incremental cache rarely helps agents: noEmit builds store no declaration
signatures, so the first edit to any file after a cold check re-checks every
transitive importer (a comment in src/shared/constants.ts re-checks all 18k files).
pnpm tc / tc:node / tc:web / tc:cli now pick the Bun from config/.bun-version when
it is on PATH and fall back to tsc with a one-line hint otherwise;
--compiler=native forces tsc. The pinned-Bun probe is shared with the
localization extraction check.
* build: pin Bun as a devDependency and make it the only default checker
The PATH probe left anyone without the exact pinned Bun (including a 1.4.2
global) on tsc's expensive path. bun@1.4.3 is now a devDependency, its
postinstall is allowed, and pnpm tc / typecheck:ci run that binary. A missing
binary is an error pointing at pnpm install rather than a silent fallback;
--compiler=native still selects tsc. A test keeps the devDependency equal to
config/.bun-version.
* ci: link the pinned Bun after the script-free install
--ignore-scripts leaves node_modules/.bin/bun as bun's postinstall stub, so the
typecheck runner found no binary and any pnpm-run script calling bun would hit
the stub before setup-bun's copy. pnpm rebuild bun runs only that allowed build.
