fix(CLI-46): bump client versions past the already-published train + add PR-time drift guard

.NET/Go/Python/Rust clients (plus Contracts, which releases in lockstep
with the .NET Client) move 0.2.0 -> 0.2.1; Java moves 0.2.1 -> 0.2.2. This
starts the next release train the finding recommended, since post-publish
source changes (including the Python connect() event-loop fix, a8f86b5)
had been sitting at already-published version numbers for nine days with
nothing recording the divergence.

- Note the pypi 0.2.0 connect() defect and its supersession by 0.2.1 in
  clients/python/README.md and docs/ClientPackaging.md.
- Add scripts/check-client-versions.ps1: a PR-time guard that finds each
  client's latest publish tag (clients/go/vX.Y.Z for Go, the only client
  with a git tag; the other four publish straight to a registry with no
  tag, so the check reports "no tags found" and passes for them) and fails
  if clients/<lang> changed since that tag while the version constant
  still equals the tag's version. Wired into .gitea/workflows/ci.yml's
  portable job next to the codegen freshness checks (needs fetch-depth: 0
  for tag history).
- Mark remediation batch A Done in
  archreview/2026-08-19/remediation/00-tracking.md.

Verified on macOS: dotnet build clients/dotnet/...slnx (pass), cargo check
--workspace (pass), python -m pytest (168 passed, 1 skipped), gradle test
with JDK 17 (pass, no generated-tree churn to revert this time), gofmt -l
+ go build ./... + go test ./... (clean), and
scripts/check-client-versions.ps1 via pwsh (pass; also verified it fails
correctly when a version constant is rolled back).

clients/rust/Cargo.lock

@@ -590,7 +590,7 @@ checksum = "1d87ecb2933e8aeadb3e3a02b828fed80a7528047e68b4f424523a0981a3a084"
 
 [[package]]
 name = "mxgw-cli"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
  "clap",
  "futures-util",
@@ -1490,7 +1490,7 @@ dependencies = [
 
 [[package]]
 name = "zb-mom-ww-mxgateway-client"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
  "futures-core",
  "futures-util",

clients/rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "zb-mom-ww-mxgateway-client"
-version = "0.2.0"
+version = "0.2.1"
 edition = "2021"
 authors = ["Joseph Doherty"]
 description = "Async Rust client for the MxAccessGateway gRPC service, including a lazy-browse walker over the Galaxy Repository hierarchy."
@@ -25,7 +25,7 @@ resolver = "2"
 
 [workspace.package]
 edition = "2021"
-version = "0.2.0"
+version = "0.2.1"
 authors = ["Joseph Doherty"]
 license = "Proprietary"
 repository = "https://gitea.dohertylan.com/dohertj2/mxaccessgw"