test: migrate adapter tests off process.platform/version mutation (#186)

[debugmcpdev]

Summary

Fixes #186 — removes all 68 Object.defineProperty(process, 'platform'|'version') / vi.spyOn(process, 'platform') mutation sites across 8 adapter-package test files by extending the seam pattern #183 (PR #185) established. No production behavior changes: every new parameter defaults to the real process.platform / process.arch / process.version.

Production seams added

Package	Seam
shared	AdapterPolicy.getAdapterSpawnConfig interface gains optional trailing platform/arch params (mirrors the existing resolveExecutablePath precedent); RustAdapterPolicy implements them. Source-compatible: the 7 other policy implementations and both call sites in dap-proxy-worker.ts need no changes.
adapter-rust	RustDebugAdapter constructor-injects platform (mirrors GenericAdapterManager); all 10 method-body reads use this.platform. getRustBinaryPath / findDlltoolExecutable gain trailing platform params.
adapter-python	findPythonExecutable gains a trailing platform param, threaded into CommandFinder.find(cmd, platform?); WhichCommandFinder branches on the param (ComSpec fallback, Path→PATH copy, Store-alias filter).
adapter-dotnet	listDotnetProcesses, getProcessExecutablePath, getProcessExecutableDir, getProcessArchitecture gain trailing platform params (the latter two thread through).
adapter-ruby	getRubySearchPaths, getRdbgSearchPaths, findRubyExecutable, findRdbgExecutable gain trailing platform params (completes the file buildRdbgInvocation started in #183).
adapter-javascript	JavascriptAdapterFactory.validate gains a trailing nodeVersion param (override-compatible with IAdapterFactory.validate()).

Tests now pass 'win32'/'linux'/'darwin' (or 'v12.22.0') explicitly; all save/restore machinery is deleted (−184 net lines). The rust toolchain tests construct per-test adapters with an explicit platform instead of mutating the beforeEach one. A side benefit: the win32-x64 codelldb assertion in adapter-policy-rust.test.ts now passes an explicit 'x64' arch, making it hermetic on arm64 hosts.

Acceptance (from the issue)

• rg -n "defineProperty\(process|spyOn\(process,\s*'platform'|spyOn\(process,\s*'version'" over the whole repo returns nothing (baseline: 68 hits in 8 files)
• No production behavior change when parameters are omitted

Verification

• All 11 affected test files: 218/218 pass
• Full unit sweep under LEAK_GUARD_STRICT=1: 154 files / 2488 tests pass
• pnpm run build (full workspace typecheck) clean; lint clean
• Pre-push hook: unit + integration green

Refs #183, #159.

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 88.46154% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
packages/adapter-dotnet/src/utils/dotnet-utils.ts	66.66%	3 Missing ⚠️
packages/adapter-rust/src/utils/rust-utils.ts	66.66%	2 Missing ⚠️
packages/adapter-python/src/utils/python-utils.ts	88.88%	1 Missing ⚠️

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