Move apps/web to TypeScript 7 once @astrojs/check supports it

[zachdunn]

Summary

apps/web is the one workspace package still on TypeScript ^6.0.3. Everything else moved to 7.0.2 in #609. This tracks finishing the job once Astro supports it.

Why it's blocked

@astrojs/check@0.9.10 (latest at time of writing) declares:

"peerDependencies": { "typescript": "^5.0.0 || ^6.0.0" }

TypeScript 7 is excluded upstream, so this isn't something a version bump on our side can fix.

The underlying cause is that TypeScript 7's npm package no longer ships the JS compiler API — its main export is just lib/version.cjs, with ts.createProgram and the language service moved behind typescript/unstable/*. @astrojs/check reaches the API through @astrojs/language-server → @volar/typescript, so on TS7 it fails at startup:

Cannot read properties of undefined (reading 'fileExists')
  at AstroCheck.getTsconfig (@astrojs/language-server/dist/check.js:162)

Note this is specific to astro check. astro build already works on TypeScript 7 (verified, exit 0) — it goes through esbuild/vite and never touches the TS API. So there's no build risk here, only type coverage.

Why we didn't work around it

Two options were tested during #609 and both rejected:

• Aliasing a second TypeScript (typescript@6 for astro check + an aliased 7 for tsc) doesn't work cleanly. pnpm resolves a peer dep from the host package, so @astrojs/check would still receive 7. It would need a real typescript@6 plus an alias whose tsc bin collides in .bin, invoked by absolute path.
• Dropping astro check trades away far more than it gains. tsconfig.worker.json — web's only direct tsc use — covers 4 files. astro check covers 149. Upgrading would speed up 4 files and remove type coverage from 149.

Waiting is the right call.

Trigger

Astro ships a @astrojs/check (or @astrojs/language-server / @volar/typescript) release whose typescript peer range admits ^7. Worth re-checking periodically:

npm view @astrojs/check peerDependencies --json

The change

One line in apps/web/package.json:

-    "typescript": "^6.0.3",
+    "typescript": "^7.0.2",

Then pnpm install and confirm pnpm --filter @uploads/web typecheck passes — that script runs wrangler types && astro check && tsc -p tsconfig.worker.json --noEmit, so it exercises the whole path. Baseline to match: 150 files, 0 errors.

Watch for TS5011 (TypeScript 7 rejects an inferred rootDir) if any emit config is touched — that's the one behavior change we hit in #609.

Done when

• apps/web is on typescript@^7
• astro check passes at 0 errors
• All 12 workspace packages report the same TypeScript major