deps: bump @stryker-mutator/core and vitest-runner to 9.6.1

[Chris0Jeky]

Summary

• Bumps @stryker-mutator/core from 8.7.1 to 9.6.1
• Bumps @stryker-mutator/vitest-runner from 8.7.1 to 9.6.1
• Both packages share a peer dependency and must be upgraded together

This combines the individual Dependabot PRs #828 (@stryker-mutator/core) and #829 (@stryker-mutator/vitest-runner), which each failed CI because they only bumped one side of the peer dependency pair.

Verification

• npm ci -- clean install succeeds with both at 9.x
• vue-tsc --noEmit -- typecheck passes
• npm run build -- full production build passes
• npx vitest --run -- all 2452 unit tests pass (205 test files)
• Stryker config (stryker.config.mjs) requires no changes for 9.x
• npm ls @stryker-mutator/core @stryker-mutator/vitest-runner confirms both at 9.6.1, deduped

Test plan

• npm ci succeeds
• Typecheck passes
• Full build passes
• All 2452 unit tests pass
• CI pipeline passes

[Chris0Jeky]

Self-review

Changes reviewed: package.json and package-lock.json only.

package.json: Exactly 2 lines changed -- both @stryker-mutator/core and @stryker-mutator/vitest-runner bumped from ^8.7.1 to ^9.6.1. No other dependencies affected.

package-lock.json: Lockfile updates reflect the new Stryker 9.x dependency tree. Net reduction in transitive dependencies (452 additions vs 571 deletions) -- Stryker 9.x appears to have a leaner dependency graph.

Stryker config: stryker.config.mjs reviewed -- all options (packageManager, reporters, testRunner, vitest, coverageAnalysis, thresholds, mutate, tempDirName, cleanTempDir, timeoutMS, timeoutFactor) remain valid in 9.x. The @stryker-mutator/api/core type import resolves correctly. No config changes needed.

Verification results:

• npm ci -- clean install succeeds
• vue-tsc --noEmit -- typecheck passes
• npm run build -- production build passes (97 precached PWA assets)
• npx vitest --run -- all 2452 tests pass across 205 test files
• npm ls confirms both packages at 9.6.1, properly deduped

Risk assessment: Low. This is a dev-only dependency (mutation testing tooling) that does not affect production builds or runtime behavior. The upgrade is straightforward with no breaking changes affecting our configuration.

[Copilot]

Pull request overview

Updates the frontend mutation-testing toolchain by upgrading Stryker JS core and its Vitest runner together to satisfy their peer dependency relationship and restore CI stability for Dependabot-driven bumps.

Changes:

• Bump @stryker-mutator/core from 8.7.1 to 9.6.1
• Bump @stryker-mutator/vitest-runner from 8.7.1 to 9.6.1
• Refresh package-lock.json to reflect the new Stryker dependency graph

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
frontend/taskdeck-web/package.json	Updates Stryker core + vitest runner devDependency versions to 9.6.1 in tandem.
frontend/taskdeck-web/package-lock.json	Locks the upgraded Stryker packages and their updated transitive dependencies.

Files not reviewed (1)

• frontend/taskdeck-web/package-lock.json: Language not supported

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[gemini-code-assist]

Code Review

This pull request upgrades @stryker-mutator/core and @stryker-mutator/vitest-runner from version 8.7.1 to 9.6.1, which involves extensive updates to transitive dependencies in the lockfile. The review feedback suggests pinning these packages to exact versions rather than using caret ranges to prevent potential peer dependency conflicts, as the vitest-runner requires a specific version of the core package to function correctly.

[gemini-code-assist]

The @stryker-mutator/vitest-runner package version 9.6.1 has a strict peer dependency on @stryker-mutator/core at exactly version 9.6.1 (as seen in the lockfile). Using the caret (^) range in package.json allows npm to install a newer version of the core package (e.g., 9.7.0) while keeping the runner at 9.6.1, which will lead to peer dependency conflicts and installation failures. It is recommended to use exact versions for these packages to ensure they remain in sync, especially since they must be upgraded together as noted in the PR description.

Suggested change

	"@stryker-mutator/core": "^9.6.1",
	"@stryker-mutator/vitest-runner": "^9.6.1",
	"@stryker-mutator/core": "9.6.1",
	"@stryker-mutator/vitest-runner": "9.6.1",