fix(cli-integ): exclude TypeScript 7.x from the init-typescript-app matrix

[iankhou]

Summary

TypeScript 7.0.2 — the first stable release of the Go-based compiler — was published to npm on 2026-07-08 at 15:55 UTC. The init-typescript-app integ test enumerates TypeScript minor versions dynamically from npm at runtime, so 7.0 immediately entered the test matrix on every PR.

The test installs typescript@7.0 alongside ts-node@^10 and runs cdk synth through ts-node — which is incompatible with TypeScript 7 (the Go compiler no longer exposes the ts.sys API ts-node reads its configuration through). Every run since the release crashes:

TypeError: Cannot read properties of undefined (reading 'fileExists')
    at readConfig (.../ts-node/dist/configuration.js:91:33)

This fails the four integ_init-templates (init-typescript-app, *) jobs on every PR, regardless of content (first observed on #1676; the last passing run started 26 minutes before the 7.0.2 publish). The crash reproduces standalone with no CDK involvement:

npm install typescript@7.0 ts-node@^10 && npx ts-node anything.ts

Fix

Bound the version enumeration in typescriptVersionsSync to <7.0. The resulting matrix (3.9 through 6.0) is identical to what ran — and passed — before the release. Verified against npm that the fixed range excludes 7.0 and drops nothing else.

Follow-up

Testing the init template against TypeScript 7 needs a synth toolchain that supports it (a ts-node replacement such as tsx, or Node's native type stripping) — that's a template change, not a test-matrix change, so it's left out of this unblocking fix.

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[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.59%. Comparing base (4086fdf) to head (063e9ba).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1718   +/-   ##
=======================================
  Coverage   89.59%   89.59%           
=======================================
  Files          77       77           
  Lines       11758    11758           
  Branches     1651     1651           
=======================================
  Hits        10534    10534           
  Misses       1195     1195           
  Partials       29       29           

Flag	Coverage Δ
suite.unit	89.59% <ø> (ø)

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