Fix test step summary with verbose go test output

[dcbickfo]

• Added -v flag to go test in test.sh so CI gets individual test names
• Step summary now correctly counts individual tests via ^--- PASS:, ^--- FAIL:, ^--- SKIP: patterns
• Failed tests are listed by name in a collapsible details section
• Previous summary was broken: grepped for verbose patterns but test.sh ran without -v, so all counts showed 0

Tested on inventory-api: https://github.com/wishabi/inventory-api/actions/runs/23457990255

[Copilot]

Pull request overview

Updates the Go composite action’s GitHub step summary to correctly parse default (non--v) go test output, reporting results at the package level.

Changes:

• Switch summary parsing from verbose test-case markers (--- PASS/FAIL/SKIP) to package-level go test lines (ok, FAIL, [no test files]).
• Rename the summary table columns/labels to reflect package-level counts.
• Update the failure details section to list failed packages rather than failed tests.

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[Copilot]

Pull request overview

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

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