feat: align all components to SemVer 2.0 for version comparison

[JusterZhu]

Summary

Replace all System.Version usage across Core, Extension, and Drivelution with a unified Semver utility class following SemVer 2.0, aligned with GeneralUpdate.Infrastructure.Common/Utilitys/Semver.cs.

All NuGet packages are already versioned as 10.5.0-beta.2 (valid SemVer 2.0), but the SDK code could not compare such versions because System.Version.TryParse("10.5.0-beta.2") returns false, causing silent "no update" behavior. This PR fixes that.

Key changes

• Core: DownloadPlanBuilder, OssStrategy, ClientStrategy — all Version.TryParse/new Version() → Semver.TryParse + SemVersion operators
• Extension: VersionCompatibilityChecker — same migration
• Drivelution: VersionComparer → [Obsolete] wrapper delegating to new Semver
• Default: ClientVersion from "1.0.0.0" → "1.0.0"
• 3 new files: Utilities/Semver.cs in each of Core, Extension, Drivelution

Bugs fixed incidentally

1. CVP matching never worked — old fromVer == localVersion used reference equality on Version (class), always false
2. OssStrategy NPE guard — assets.Max()!.Value on empty parsed collection

Backward compatibility

• Legacy 4-part versions ("1.0.0.0") accepted and normalized
• 3-part SemVer comparisons produce identical results
• VersionComparer preserved as [Obsolete] delegate

Closes #520

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This pull request replaces System.Version-based version parsing/comparison across Core, Extension, and Drivelution with a SemVer 2.0-compatible Semver utility (including prerelease handling and legacy 4-part normalization), preventing “silent no update” behavior when versions include prerelease suffixes.

Changes:

• Added SemVer 2.0 parsing/comparison utilities to Core, Extension, and Drivelution; updated comparison call-sites to use Semver/SemVersion.
• Updated default ClientVersion to "1.0.0" and aligned examples/docs/tests accordingly.
• Marked Drivelution VersionComparer as [Obsolete] and delegated implementation to Semver; updated Drivelution tests to match new behavior.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
tests/DrivelutionTest/Utilities/VersionComparerAndRestartHelperTests.cs	Updates expectations to match SemVer-based comparison behavior (invalid/overflow inputs return 0, legacy 4-part accepted).
tests/CoreTest/Configuration/UpdateConfigurationTests.cs	Adjusts assertion for new default client version string (1.0.0).
src/c#/GeneralUpdate.Extension/Utilities/Semver.cs	Adds SemVer 2.0 parsing/normalization/comparison implementation for Extension.
src/c#/GeneralUpdate.Extension/Examples/ExtensionExample.cs	Updates example host version to 3-part SemVer.
src/c#/GeneralUpdate.Extension/Compatibility/VersionCompatibilityChecker.cs	Migrates host/version constraint checks and “latest compatible” selection to SemVer comparisons.
src/c#/GeneralUpdate.Drivelution/Core/Utilities/VersionComparer.cs	Converts existing comparer into an obsolete wrapper delegating to Semver.
src/c#/GeneralUpdate.Drivelution/Core/Utilities/Semver.cs	Adds SemVer 2.0 parsing/normalization/comparison implementation for Drivelution.
src/c#/GeneralUpdate.Core/Utilities/Semver.cs	Adds SemVer 2.0 parsing/normalization/comparison implementation for Core.
src/c#/GeneralUpdate.Core/Strategy/OssStrategy.cs	Switches OSS version filtering and LastVersion computation to SemVer parsing/comparison.
src/c#/GeneralUpdate.Core/Strategy/ClientStrategy.cs	Updates failed-version guard logic to use SemVer parsing/comparison.
src/c#/GeneralUpdate.Core/Download/DownloadPlanBuilder.cs	Migrates update planning/version filtering to SemVer; adjusts CVP matching logic.
src/c#/GeneralUpdate.Core/Configuration/VersionIdentity.cs	Updates version string documentation example to SemVer 3-part format.
src/c#/GeneralUpdate.Core/Configuration/VersionEntry.cs	Updates version string documentation example to SemVer 3-part format.
src/c#/GeneralUpdate.Core/Configuration/UpdateRequestBuilder.cs	Updates JSON example to use "1.0.0" for ClientVersion.
src/c#/GeneralUpdate.Core/Configuration/UpdateConfiguration.cs	Changes default ClientVersion from "1.0.0.0" to "1.0.0".
src/c#/GeneralUpdate.Core/Configuration/AppMetadataDiscoverer.cs	Updates comment examples to reflect the new default client version format.

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[JusterZhu]

All 5 Copilot review suggestions have been addressed across 4 fix commits:

#	Suggestion	Fix commit	Status
1	SemVersion? lifted > operator → bool? in Where(...)	e8832c32 — extracted .Value before comparison	✅
2	Missing using System.Linq for string.All()	840fe535 — added using System.Linq to all 3 Semver.cs	✅
3	Same as #2 for Extension copy	840fe535	✅
4	Same as #2 for Drivelution copy	840fe535	✅
5	SemVersion? >= SemVersion? → bool? in IsCompatible	e8832c32 — used .Value on both sides	✅

Additional fixes:

• SysNumOverflow only checks MAJOR.MINOR.PATCH triplet (not prerelease/build metadata) — 3a4c9672
• Drivelution tests updated for aligned Semver semantics — 32bd4533

CI is now ✅ green.