fix(ci): use explicit test path — glob not expanded by sh on Linux

[furic]

Summary

• The npm test script used test/**/*.test.ts which relies on shell glob expansion
• On Linux CI (sh), ** globbing requires globstar (a bash extension) — sh passes it as a literal path and Node can't find it
• Fixed by using the explicit path test/util.test.ts (as long as we have one test file this is the right approach; add new files explicitly as the suite grows)

Test plan

• CI validate job passes (typecheck + format:check + unit tests)
• npm run dev with TSCO.L (GBp) + SAP.DE (EUR) added to targetPortfolio — verify header shows · USD, prices are USD-magnitude, footer caveat appears, original currencies logged in console
• Revert config

Closes the CI failure from the squash-merge of #10.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Fixes Linux CI failures caused by relying on sh to expand ** globs in the npm test script by switching to an explicit test file path.

Changes:

• Update npm test to run test/util.test.ts explicitly instead of test/**/*.test.ts

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[Copilot]

The test script is now hard-coded to a single file (test/util.test.ts), so any additional test files added later will be silently skipped unless the script is updated. If the goal is to avoid ** globbing on sh while still picking up multiple tests, consider using a POSIX-safe pattern like test/*.test.ts (or a directory-based invocation if supported) so new tests in test/ run automatically.

Suggested change

	"test": "node --import=tsx/esm --test test/util.test.ts",
	"test": "node --import=tsx/esm --test test/*.test.ts",