fix: expose native replay substrates through launcher

[abrichr]

Outcome

Completes the launcher path for the released native and remote Flow substrates.

• openadapt flow replay is an argv-transparent Flow passthrough, so Flow owns every current and future backend, target, config, effect, durable, worklist, and governance flag.
• Launcher extras install the applicable Windows, macOS, Linux, RDP, and Capture dependencies with OS-only bindings correctly platform-marked.
• Engine/capture floors are Flow 1.20.1 and Capture 1.0.4.
• Onboarding separates interactive local capture from replay against a native app, WAA agent, RDP framebuffer/window, or exact Citrix Workspace window.
• Browser, Windows, macOS, Linux, RDP, and Citrix/VDI are consistently labeled Available while preserving per-application/deployment evidence boundaries and Citrix ica_hdx_accepted=false.
• Hero accessibility/PyPI fallback copy is covered by a regression test so stale maturity labels cannot return unnoticed.

Verification

• uv run pytest -q — 49 passed, 1 expected CI-only skip
• Ruff check and format — passed
• wheel/sdist build and release artifact verification — passed
• wheel SHA-256: 8c4c45ca8082a0ac04e4e445ea3d34db0b5495a65a743222afe05f6d16ad26b2
• sdist SHA-256: 412ae5096445f04d0addd67a5bca4bc6a672f5409487179194a62c8917b467fb

Base: bbfcf8fe07ca1565bd8472616c7b210810105744

Head: 405f18f7255dabc4432e40ac2e2c75b3b55459b4