feat: Add watchOS support to the TS driver, functional tests, and release pipeline

[mykola-mokhnach]

Summary

Wires watchOS all the way through the Node/TypeScript driver, the functional test suite, and the release pipeline, building on the native watchOS support and CI (#1209, #1215, #1216) landed earlier.

Changes

TS driver (lib/)

• isWatchOS, three-way (iOS/tvOS/watchOS) scheme, SDK, and deployment-target selection in xcodebuild.ts, a generalized bundleWDASim, and simulator-only xctestrun naming for watchOS.
• Real watchOS device requests now throw a clear error at WebDriverAgent construction time — watchOS is simulator-only, there's no real-device WDA distribution/testing story for it.

Functional tests

• Rewritten to assume the CI workflow (or the developer, locally) has already booted and settled the target simulator — no more per-test simulator create/boot/teardown.
• getTargetDevice() (test/functional/helpers/simulator.ts): in CI, requires SIMULATOR_UDID (fails loudly if unset — CI must never boot its own simulator here); locally, boots the existing device matching DEVICE_NAME if needed, and lists available simulators if none match. Never creates a new device.
• PLATFORM_NAME/PLATFORM_VERSION/DEVICE_NAME (test/functional/desired.ts) are now mandatory env vars, no guessed defaults.
• Two scenarios per platform: build-and-start-from-sources, and start-from-a-prebuilt-binary (usePrebuiltWDA), both driven by real positive-path checks — GET /status, session-less GET /source, and session-scoped GET /session/:id/source via a real WDA-issued session (the sessionId passed to launch() is Appium-side only and never reaches WDA).
• afterEach always calls agent.quit(), so a failed assertion can't leave a leftover WDA process/port for the next test.

CI

• functional-test.yml: adopts futureware-tech/simulator-action@v5 (matching appium-xcuitest-driver's current setup, including the Xcode 27 → DeviceHub.app fix) instead of hand-rolled xcrun simctl scripting, plus two new watchOS matrix rows (Min/Max Xcode, matching wda-tests.yml's existing pairing).
• Scripts/ci/wait-for-simulator-idle.mjs (new): polls the simulator's process-tree CPU usage and waits for it to settle before tests run, ported from appium-xcuitest-driver's stability fix — takes the simulator UDID directly from simulator-action's output.
• publish.js.yml / wda-package.yml: watchOS simulator (arm64 + x86_64) build entries, mirroring the existing tvOS entries. No real-device entry.

Tooling

• npm run bundle:watch added alongside bundle:ios/bundle:tv.

Notes

• publish.js.yml's release job only runs if build-wda succeeds for every matrix entry, so a broken watchOS build would now also block iOS/tvOS releases — the same coupling that already exists for tvOS today, just extended to a third platform.