feat(flags): add semver targeting to local evaluation

[dmarticus]

Summary

• Add 9 semver comparison operators to local feature flag evaluation
• Implement inline semver parsing (no external dependencies)
• Add 45 comprehensive tests

What

This PR adds semver (semantic versioning) targeting support to local feature flag evaluation, matching the behavior already implemented in the Python SDK and PostHog server.

New operators

Operator	Description	Example
semver_eq	Exact match	1.2.3 == 1.2.3
semver_neq	Not equal	1.2.3 != 1.2.4
semver_gt	Greater than	1.2.4 > 1.2.3
semver_gte	Greater than or equal	1.2.3 >= 1.2.3
semver_lt	Less than	1.2.2 < 1.2.3
semver_lte	Less than or equal	1.2.3 <= 1.2.3
semver_tilde	Patch-level range	~1.2.3 means >=1.2.3 <1.3.0
semver_caret	Compatible-with range	^1.2.3 means >=1.2.3 <2.0.0
semver_wildcard	Wildcard range	1.2.* means >=1.2.0 <1.3.0

Semver parsing

The parseSemver function handles:

• v/V prefix stripping (v1.2.3 → 1.2.3)
• Whitespace trimming
• Pre-release suffix stripping (1.2.3-alpha → 1.2.3)
• Build metadata stripping (1.2.3+build → 1.2.3)
• Partial versions (1.2 → 1.2.0, 1 → 1.0.0)
• Extra parts ignored (1.2.3.4 → 1.2.3)
• Leading zeros (01.02.03 → 1.2.3)

Invalid inputs throw InconclusiveMatchException following the existing error handling pattern.

Test plan

• All 45 new semver tests pass
• Existing property matching tests still pass
• PHP syntax validation passes