feat: add icon visibility controls and suppress silent captions

[Nowhitestar]

Settings now let users hide the Dock and menu bar icons independently while native shortcuts and recording controls keep running. Audio evidence and timestamp/channel alignment prevent silence, low room tone, DC offset, isolated clicks and stale speech from authorizing spurious xAI captions.

The separate English and Chinese READMEs are shorter, explain the design choices, and use fictional screenshots without embedded metadata. Detailed setup stays in the linked guides. The public Phase 13 record reconciles old issue status while keeping the private local acceptance journal unpublished and unperformed historical tests explicit.

The reminder reload test now waits until the restarted fixture has installed its signal handler. Previously, an immediate SIGHUP could terminate that child before setup and fail cleanup on macOS. Product signal handling and permission checks are unchanged.

Validation:

• 150 documentation/release/packaging checks and 7 reminder-service tests passed locally.
• Typecheck passed with all five dependency updates. The full local Vitest run passed 1,923 tests; its four environment-dependent failures are covered by a successful focused rerun of all six local-caption tests using the existing Command Line Tools.
• The feature changes previously passed targeted transcription/configuration/UI regressions and 20 native checks. Signed local App build 1694 was installed and checked on September 28 for Host/Capture health, database/config preservation and actual icon switching; this is not a new public release.
• Final GitHub CI passed on 9e61b70: Python tests, Swift build, native navigation, typecheck, Vitest, web build, bundled Host and rendered Settings checks. This validates the feature and merged dependencies build(deps): bump qs from 6.15.3 to 6.16.0 in /yulu/scripts/yulu_ui #176, build(deps): bump hono from 4.13.4 to 4.13.7 in /yulu/scripts/yulu_ui #198, build(deps): bump @vitest/mocker and vitest in /yulu/scripts/yulu_ui #199, chore(deps): bump fast-uri from 3.1.6 to 3.1.8 in /yulu/scripts/yulu_ui #226 and build(deps): bump ip-address from 10.5.0 to 10.7.2 in /yulu/scripts/yulu_ui #227 together. The merged main tree at 6db2a60 is identical to the tested tree.

Historical issue closeout: #200, #171, #145.