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).

.gitea/workflows/ci.yml

@@ -23,7 +23,12 @@ jobs:
     # tests, the codegen/descriptor freshness guards, and the clients that build on Linux.
     runs-on: ubuntu-latest
     steps:
+      # fetch-depth: 0 (full history + tags): the CLI-46 client-version-freshness check below
+      # diffs each client's source against its last publish tag (e.g. clients/go/vX.Y.Z), which
+      # a shallow, tagless checkout cannot resolve.
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - uses: actions/setup-dotnet@v4
         with:
@@ -77,6 +82,15 @@ jobs:
         shell: pwsh
         run: ./scripts/check-codegen.ps1
 
+      # CLI-46: catches a client whose source changed since its last publish
+      # tag while the version constant still reads that tag's already-shipped
+      # number — the drift the pack-clients.ps1/tag-go-module.ps1 collision
+      # guards only catch at actual publish time. Needs tag history, hence
+      # `fetch-depth: 0` on this job's checkout above.
+      - name: Client version freshness
+        shell: pwsh
+        run: ./scripts/check-client-versions.ps1
+
       - name: Gateway fake-worker tests
         run: dotnet test src/ZB.MOM.WW.MxGateway.Tests/ZB.MOM.WW.MxGateway.Tests.csproj -c Release --no-build