fix(CLI-39): bump Contracts nupkg to 0.2.0; scope pack-clients.ps1 regexes

Code review of the CLI-39 branch caught an Important gap: Contracts.csproj
was left at the already-published 0.1.2 while the .NET Client moved to
0.2.0. Invoke-PackDotnet in scripts/pack-clients.ps1 packs and publishes
both ZB.MOM.WW.MxGateway.Contracts and .Client through the same -Publish
loop, and the new collision guard runs every nupkg it finds through
Assert-GiteaPackageNotPublished. Left as-is, the next real .NET publish
would pack Contracts at 0.1.2, the guard would correctly refuse to
republish it, and the loop would abort mid-way with Client (alphabetically
first) possibly already pushed -- the two packages permanently out of
lockstep.

- src/ZB.MOM.WW.MxGateway.Contracts/ZB.MOM.WW.MxGateway.Contracts.csproj:
  <Version> 0.1.2 -> 0.2.0, matching the .NET Client (they have always
  released together).
- src/Directory.Build.props: corrected a comment that was now stale --
  it claimed the repo-wide 0.1.2 default was kept to match the Contracts
  package, which is no longer true now that Contracts.csproj overrides it.
  The <Version> value itself is unchanged; Server/Worker/Tests staying at
  0.1.2 is a separate, not-yet-made decision, out of scope for CLI-39.
- docs/ClientPackaging.md: Contracts.csproj added as a fifth manifest in
  the Versioning section, with the near-miss recorded.

Also hardened scripts/pack-clients.ps1 per the same review: the Python
(pyproject.toml) and Rust (Cargo.toml) version-extraction regexes now
scope to the [project]/[package] section header instead of matching the
first "version = ..." line anywhere in the file (Cargo.toml has an
identical second one under [workspace.package] -- matching whichever came
first was luck of ordering, not correctness). One-line comment added on
the nuget filename-parse regex.

Verified live against the real Gitea registry: Contracts and Client both
still refuse at 0.1.2 and both now pass at 0.2.0, including running the
actual Invoke-PackDotnet filename-parse-then-guard logic against two
freshly packed real .nupkg files. dotnet build of Contracts.csproj and the
client slnx both clean. No publish performed.

src/Directory.Build.props

@@ -11,10 +11,14 @@
 
   <!-- TST-11: single-source the .NET-side version for Server, Worker, Contracts, and tests
        (they otherwise stamp the SDK default 1.0.0, so a deployed gateway cannot be correlated
-       to a release). Kept at 0.1.2 to match the Contracts package and the aligned Python/Rust/
-       Go clients; the Java client leads at 0.2.0 after its JDK-17 retarget. The git short SHA is
-       appended to InformationalVersion (0.1.2+<sha>) so support can map a running binary to a
-       commit; the query is guarded so a build outside a git checkout still succeeds. -->
+       to a release). Server/Worker/Tests stay at this default. CLI-39 (2026-08-07) moved the
+       published `ZB.MOM.WW.MxGateway.Contracts` and `.Client` nuget packages to 0.2.0 via an
+       explicit <Version> override in Contracts.csproj (MSBuild property-last-write-wins over
+       this Directory.Build.props default) — Server/Worker assembly stamping and the published
+       client packages are deliberately decoupled; a broader 0.2.0 alignment for Server/Worker
+       is a separate, not-yet-made decision. The git short SHA is appended to
+       InformationalVersion (0.1.2+<sha>) so support can map a running binary to a commit; the
+       query is guarded so a build outside a git checkout still succeeds. -->
   <PropertyGroup>
     <Version>0.1.2</Version>
   </PropertyGroup>

src/ZB.MOM.WW.MxGateway.Contracts/ZB.MOM.WW.MxGateway.Contracts.csproj

@@ -7,7 +7,7 @@
   <PropertyGroup>
     <IsPackable>true</IsPackable>
     <PackageId>ZB.MOM.WW.MxGateway.Contracts</PackageId>
-    <Version>0.1.2</Version>
+    <Version>0.2.0</Version>
     <Authors>Joseph Doherty</Authors>
     <Company>ZB MOM WW</Company>
     <Copyright>Copyright (c) ZB MOM WW. All rights reserved.</Copyright>