test-label-analyzer: add filter expressions command for Ginkgo flags

[Maximus-08]

What this PR does / why we need it:

Implements the “generate strings for Ginkgo flags” use case from the test-label-analyzer design:

• New subcommand: test-label-analyzer filter expressions <matching-tests.json>
• Input: JSON produced by test-label-analyzer filter stats matching-tests (same format as existing matching-tests output).
• Output (default text): Lines suitable for --filter, --skip, and --label-filter (Ginkgo v1 text filters and v2 label filter).
• Flag: --output-mode=text|json (default text).

Typical flow: run stats → filter stats matching-tests → filter expressions to get strings to pass to ginkgo --filter / ginkgo --label-filter for the same set of tests.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #2679 (partial — filter string generation)

Special notes for your reviewer:

• New files: robots/test-label-analyzer/cmd/filter/expressions.go and expressions_test.go. No changes to existing commands.
• Deduplicates test names (for v1 filter) and category reasons (for v2 label-filter). Output format is intentionally simple (OR of literals).

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• Design: A design document was considered and is present (link) or not required
• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Testing: New code requires new unit tests. New features and bug fixes require at least on e2e test
• Documentation: A user-guide update was considered and is present (link) or not required. You want a user-guide update if it's a user facing feature / API change.
• Community: Announcement to kubevirt-dev was considered

Release note:

test-label-analyzer: add `filter expressions` subcommand to generate Ginkgo --filter/--skip and --label-filter strings from matching-tests JSON.

[kubevirt-bot]

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[sourcery-ai]

Hey - I've left some high level feedback:

• In buildExpressions, you escape double quotes but wrap values in single quotes; consider also handling embedded single quotes (or switching to double-quoted literals) so generated expressions remain syntactically valid when names/reasons contain '.
• The new expressions command currently uses an explicit len(args) < 1 check; you may want to leverage cobra's Args: cobra.ExactArgs(1) to make argument validation and usage messages more consistent with other commands.
• The header in expressions_test.go uses a 2026 copyright year, which is inconsistent with expressions.go and the rest of the project; aligning the year will avoid future confusion.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- In `buildExpressions`, you escape double quotes but wrap values in single quotes; consider also handling embedded single quotes (or switching to double-quoted literals) so generated expressions remain syntactically valid when names/reasons contain `'`.
- The new `expressions` command currently uses an explicit `len(args) < 1` check; you may want to leverage cobra's `Args: cobra.ExactArgs(1)` to make argument validation and usage messages more consistent with other commands.
- The header in `expressions_test.go` uses a 2026 copyright year, which is inconsistent with `expressions.go` and the rest of the project; aligning the year will avoid future confusion.

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[Copilot]

Pull request overview

Adds a new test-label-analyzer filter expressions subcommand intended to turn matching-tests.json (from filter stats matching-tests) into ready-to-use Ginkgo flag expressions for text filtering and label filtering.

Changes:

• Introduces filter expressions cobra command with --output-mode=text|json.
• Implements buildExpressions() to deduplicate test names and reasons and join them into OR expressions.
• Adds unit tests for buildExpressions().

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 6 comments.

File	Description
robots/test-label-analyzer/cmd/filter/expressions.go	Adds the new filter expressions command and expression-generation logic.
robots/test-label-analyzer/cmd/filter/expressions_test.go	Adds unit tests for the expression generation helper.

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[Copilot]

Pull request overview

Adds a new filter expressions subcommand to test-label-analyzer that converts matching-tests JSON into ready-to-paste Ginkgo v1 --filter/--skip and Ginkgo v2 --label-filter expressions, with optional JSON output.

Changes:

• Introduces filter expressions <matching-tests.json> Cobra command and --output-mode=text|json.
• Implements expression construction with deduplication + stable ordering.
• Adds unit tests for buildExpressions.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
robots/test-label-analyzer/cmd/filter/expressions.go	Adds the expressions command, reads matching-tests JSON, and renders Ginkgo v1/v2 expressions (text or JSON).
robots/test-label-analyzer/cmd/filter/expressions_test.go	Adds unit coverage for buildExpressions with empty + basic input.

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[kubevirt-bot]

There has been no activity on this PR for 45 days.
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/lifecycle stale