fix: preserve leading zeros in SwampVersion calver time component

[stack72]

Summary

Fixes #439

SwampVersion.create() uses parseInt() to parse calver version segments into integers for comparison. However, toString() was reconstructing the version string from those integers, which strips leading zeros. This is a problem for builds between midnight and ~09:59:59 UTC, where the HHMMSS time component has leading zeros (e.g. 003901).

Example of the bug:

Input:    "20260224.003901.0"
Parsed:   major=20260224, minor=3901, patch=0
Output:   "20260224.3901.0"  ← leading zeros lost
Expected: "20260224.003901.0"

This caused .swamp.yaml version round-tripping to fail — the version written back after parsing didn't match the original, breaking UAT validation for early-morning builds.

Fix

Store the original string segments (rawVersion) alongside the parsed integer values. toString() now returns the preserved raw string instead of reconstructing from integers. The integer fields (major, minor, patch) remain unchanged and continue to be used for compareTo, equals, isNewerThan, and isOlderThan.

This approach preserves exact round-tripping for all version formats:

• Calver: "20260224.003901.0" → toString() → "20260224.003901.0"
• Semver: "1.2.3" → toString() → "1.2.3"
• With suffix: "20260224.003901.0-sha.abc123" → toString() → "20260224.003901.0" (suffix correctly stripped, zeros preserved)

Test plan

• Added regression test: create("20260224.003901.0").toString() returns "20260224.003901.0"
• Added regression test: leading zeros preserved when suffix is stripped
• All 28 existing SwampVersion tests pass (including create("1.2.3").toString() === "1.2.3")
• Full test suite passes (1877 tests)
• deno check, deno lint, deno fmt all clean

🤖 Generated with Claude Code

[github-actions]

Review Summary

This PR correctly fixes the leading zeros issue in SwampVersion calver formatting. The implementation is clean and follows project conventions.

✅ No Blocking Issues

Code Quality Assessment

TypeScript Strict Mode: ✅ Compliant

• No any types
• Proper type annotations with readonly modifiers
• Private constructor maintained for immutability

Code Style (CLAUDE.md): ✅ Compliant

• Named exports used (export class SwampVersion)
• AGPLv3 copyright header present
• Passes linting requirements per PR description

Domain-Driven Design: ✅ Well-designed

• SwampVersion is correctly implemented as a Value Object
• The rawVersion field is appropriately private - it's an implementation detail for roundtrip fidelity
• Comparison operations still use integer values, which is semantically correct since "003901" and "3901" represent the same numeric value
• Immutability preserved with readonly modifier

Test Coverage: ✅ Good

• Two regression tests added covering both cases (with and without sha suffix)
• Tests verify both the string output and numeric parsing
• Test file properly co-located with source (swamp_version_test.ts)

Security: ✅ No concerns

• Simple value object change with no security implications

Implementation Notes

The approach of storing rawVersion from regex match groups rather than reconstructing from integers is elegant - it correctly strips the suffix while preserving leading zeros in the version segments. This maintains exact roundtrip fidelity without breaking comparison semantics.

LGTM! 🎉