fix: opt generated projects into @types globals per target (TS 6)

[PAMulligan]

Fixes #119

Problem

Every project generated by setup-project.sh failed pnpm typecheck with TS2591 (process), TS2584 (console), and TS2304 (setTimeout) on all five targets. The script installs typescript@latest, which now resolves to TypeScript 6 — and TS 6 removed the automatic inclusion of node_modules/@types/*. The copied templates/shared/tsconfig.json had no types field, so @types/node was installed but never loaded. CI stayed green because the typecheck-templates job uses per-target snippet tsconfigs that do set types, with a lockfile-pinned toolchain.

Fix

Where the fix lives (acceptance criterion 3): per-target tsconfig templates, structured so the snippet tsconfigs extend the same files generated projects receive — drift between CI and generated output is now structurally impossible rather than comment-enforced.

• templates/shared/tsconfig.json → tsconfig.base.json (content unchanged), plus two thin per-target configs:
  • tsconfig.node.json — "types": ["node"], used by node, lambda, railway, fly
  • tsconfig.cloudflare.json — "types": ["@cloudflare/workers-types", "node"], used by cloudflare
• Generated projects get the per-target file as api/tsconfig.json extending the copied api/tsconfig.base.json.
• templates/snippets/tsconfig.{node,lambda,cloudflare}.json now extend the per-target templates and drop their own types — the typecheck-templates job type-checks through the exact configuration that ships.
• The cloudflare target now installs @cloudflare/workers-types (referenced by its types entry; pnpm doesn't expose transitive packages for type resolution). The sync NOTE in the script claimed this was "added per-platform below" but it never was.
• typescript is pinned to its major (^6) in the generated dev deps so the next TS major can't silently break generation; comment updated with the rationale. Snippets already pin ^6.0.2.
• node-server and docker Dockerfiles copy tsconfig.base.json into the build stage so in-image pnpm build keeps working.

CI gap closed

New generated-projects matrix job runs the real setup-project.sh for all five targets and type-checks the result. Deliberately no lockfile — it installs whatever pnpm add resolves that day, so a dependency release that breaks fresh projects fails in CI instead of only on user machines (exactly how this regression shipped).

Verification

• Reproduced first on the old config: fresh --node project, typescript@6.0.3 → the exact TS2591/TS2584/TS2304 errors from the issue.
• After the fix, generated all five targets fresh: every project resolves typescript@6.0.3 (pin written as ^6.0.3) and passes pnpm typecheck.
• pnpm build (tsc emit, the Docker build path) passes on the node target; dist/index.js emitted.
• All three snippet tsconfigs pass with the pinned snippet lockfile through the new extends chain.
• ESLint (typed rules via projectService) resolves the extends chain; generated-project lint errors drop from 53 to 11. The remaining 11 are pre-existing stylistic findings in the snippet sources, unrelated to this issue.

🤖 Generated with Claude Code