[FEAT] yaml semver marshal/unmarshal

[bbengfort]

Scope of changes

Adds YAML parsing to semver.

Type of change

• new feature
• bug fix
• documentation
• testing
• technical debt
• other (describe)

Author checklist

• I have manually tested the change and/or added automation in the form of unit tests or integration tests
• I have added new test fixtures as needed to support added tests

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Note

Medium Risk
Moderate risk because it introduces new binary/YAML encoding paths and manual byte parsing that could affect interoperability or expose edge-case panics on malformed input.

Overview
Adds YAML support for semver.Version via MarshalYAML/UnmarshalYAML, plus a new compact binary encoding with MarshalBinary/UnmarshalBinary and an ErrDataSize error for invalid payloads.

Updates semver tests to round-trip versions through binary/text/JSON more thoroughly (YAML test stub is present but skipped), and adds yaml struct tags to region.Info so region metadata can be loaded from YAML in addition to JSON/env.

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Cursor Bugbot has reviewed your changes and found 2 potential issues.

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UnmarshalBinary panics on malformed input data

Medium Severity

UnmarshalBinary never checks the return value j from binary.Uvarint. When j == 0 (buffer too small) or j < 0 (overflow), the index i fails to advance correctly, leading to reading garbage. More critically, the slices data[i : i+int(c)] for PreRelease and BuildMeta have no bounds check — a crafted or corrupted input with a large length prefix c causes an out-of-bounds panic.