fix: auto-detect SSH key instead of hardcoding id_rsa

[murilopmachado]

Summary

• Auto-detect SSH keys in priority order: id_ed25519 → id_ecdsa → id_rsa
• Add --ssh-key flag for custom key paths on clone and generate commands
• Add unit tests for key detection, override, fallback, and isSSH
• Add expandable SSH key configuration section to README

What changed

• services/cloner.go — getSSHKeyPath() now scans for available keys instead of hardcoding id_rsa
• services/cloner_test.go — new test file with 7 test cases
• flags.go — new --ssh-key flag
• main.go — wire flag to clone and generate commands
• actions/clone.go / actions/generate.go — read flag and pass to cloner
• README.md — expandable SSH key docs

Test plan

• All existing tests pass
• New tests pass: go test ./services/ -run "TestGetSSHKeyPath|TestSetSSHKeyPath|TestIsSSH" -v

[github-actions]

✅ StructLint Validation

Metric	Count
Checks passed	65
Violations	0

[github-actions]

Core Changes

• Introduced a new --ssh-key flag for clone and generate commands, allowing users to specify a custom SSH private key path.
• Enhanced the GitCloner service to auto-detect SSH keys in a prioritized order: id_ed25519, id_ecdsa, then id_rsa within the ~/.ssh directory, falling back to the specified flag if provided.
• Added comprehensive unit tests for the new SSH key detection and setting logic.

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Concerns

There are no critical concerns regarding security, performance, or logic flaws.

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Verdict

Approve: The changes are well-implemented, thoroughly tested, and address a valuable feature request without introducing any regressions or critical issues.

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Code review performed by GEMINI - gemini-2.5-flash.