Align docs with StyleGuide and add CLAUDE.md

- Rename 16 kebab-case docs to PascalCase per StyleGuide
- Move per-language client design docs from docs/ to clients/<lang>/
  alongside their READMEs
- Add ## Related Documentation sections to 15 docs that lacked one
- Fix sentence-case violations in H3 headings (StyleGuide rule)
- Update cross-references in gateway.md, client READMEs, scripts,
  and generate-proto.ps1 helpers to follow the new paths
- Add CLAUDE.md with build/test commands, the source-update
  verification matrix, the parity-first contract, and pointers
  to MXAccess and Galaxy Repository analysis sources

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/ImplementationPlanIndex.md

@@ -0,0 +1,107 @@
+# Implementation Plan Index
+
+This index defines the implementation order and a Gitea issue/milestone model
+for tracking the work.
+
+Repository:
+
+```text
+https://gitea.dohertylan.com/dohertj2/mxaccessgw
+```
+
+Implementation order:
+
+1. Gateway process
+2. MXAccess worker instance
+3. Client libraries
+
+Detailed plans:
+
+- `docs/ImplementationPlanGateway.md`
+- `docs/ImplementationPlanMxAccessWorker.md`
+- `docs/ImplementationPlanClients.md`
+
+## Gitea Milestones
+
+Recommended milestones:
+
+1. `gateway-foundation`
+2. `gateway-auth`
+3. `gateway-sessions-ipc`
+4. `gateway-grpc-events-dashboard`
+5. `mxaccess-worker-foundation`
+6. `mxaccess-worker-parity-slice`
+7. `clients-dotnet`
+8. `clients-go`
+9. `clients-rust`
+10. `clients-python`
+11. `clients-java`
+12. `integration-and-parity`
+13. `packaging-and-ops`
+
+## Gitea Labels
+
+Recommended labels:
+
+- `area:contracts`
+- `area:gateway`
+- `area:worker`
+- `area:dashboard`
+- `area:auth`
+- `area:client-dotnet`
+- `area:client-go`
+- `area:client-rust`
+- `area:client-python`
+- `area:client-java`
+- `area:tests`
+- `area:docs`
+- `type:feature`
+- `type:test`
+- `type:infra`
+- `type:docs`
+- `priority:p0`
+- `priority:p1`
+- `priority:p2`
+- `blocked`
+
+## Issue Body Template
+
+```markdown
+## Context
+
+## Deliverables
+
+## Acceptance Criteria
+
+## Tests
+
+## Dependencies
+```
+
+## Definition Of Done
+
+Every implementation issue should meet this baseline:
+
+- follows the relevant style guide in `docs/style-guides/`,
+- generated code is reproducible,
+- secrets are not logged,
+- unit tests pass,
+- docs are updated when behavior, commands, or paths change,
+- live MXAccess verification steps are documented when required.
+
+## Toolchain
+
+Use `docs/ToolchainLinks.md` for installed compiler/runtime paths. If a new
+terminal cannot find a recently installed tool, refresh PATH:
+
+```powershell
+$env:Path = [Environment]::GetEnvironmentVariable('Path','Machine') + ';' + [Environment]::GetEnvironmentVariable('Path','User')
+```
+
+
+## Related Documentation
+
+- [Gateway Implementation Plan](./ImplementationPlanGateway.md)
+- [MXAccess Worker Implementation Plan](./ImplementationPlanMxAccessWorker.md)
+- [Client Libraries Implementation Plan](./ImplementationPlanClients.md)
+- [Toolchain Links](./ToolchainLinks.md)