fix(cli): hide Windows console for remaining child-process spawns

[lorenzozanee]

What

Hide Windows console windows for three remaining child-process spawns in @hyperframes/cli missed by the earlier windowsHide coverage (#3379 in engine, #3529 in cli):

• telemetry/transport.ts flushSync() — spawns a detached node on every CLI exit to deliver queued events
• utils/clipboard.ts — where provider probe and the provider copy itself (clip.exe on Windows)
• server/portUtils.ts windowsListenerPid() — netstat lookup used by preview --list/--stop/conflict logging on Windows

Each site now passes windowsHide: true, a no-op on macOS/Linux. Three regression tests mirror the existing *.windowsHide.test.ts style.

Why

These binaries are console-subsystem on Windows, so spawning them without windowsHide pops a visible console window — including from contexts that own no console (detached preview server, exit-time flush). This closes out the remaining scope of #3500: every spawn/execFile/spawnSync site reachable on Windows in cli, studio-server, lint and engine now carries the flag.

How

One-line option additions only, following the exact pattern already merged in orphanCleanup.ts, manager.ts, preflight.ts, mediaMetadata.ts, waveform.ts, proxyTranscoder.ts, mediaValidation.ts and hevcPreviewLint.ts. No refactor, no new abstraction, no behavior change on non-Windows platforms.

Test plan

• Unit tests added/updated — 3 new suites (transport, clipboard, portUtils windowsHide tests) fail on base with the flag missing and pass after the fix; existing portUtils.test.ts and all runnable *.windowsHide.test.ts suites pass; oxlint/oxfmt clean; tsc --noEmit shows only pre-existing missing-generated-file errors
• Manual testing performed — the symptom is Windows-only console flashing; validated via mocked regression tests on Linux (no Windows runner available)
• Documentation updated (if applicable) — no user-facing behavior or docs change

Closes #3500

Supersedes #3956（原PR分支已删，按原提交重建）