docs: refresh docs to match the current state, add GUI/CLI/troubleshooting

The README still listed the settings UI as "todo" and its quick start told
users to download models into the working directory; phase 3 still described
the caption window's close button as "quit" and used the wrong binary name.
Bring the docs up to date and fill the gaps: a GUI guide (first run, settings
tabs, tray, download, verify), a full CLI option reference marking the
test-only flags, a troubleshooting page, the model registry's size/sha256
fields plus a licence/size table, the RTF measurement caveat (llama-cli 0.19
vs the in-process 0.56), and a note that the streaming-ONNX backend has its
own code path. phase0/phase1 experiment docs are marked as historical.

文档与现状对齐：README 的 Phase 4 从「待做」改为完成、快速开始不再让人把模型下到当前
目录；phase3 的 ✕ 说明改为「隐藏到托盘」、用法改用 live-caption；新增 GUI/CLI/排错三份
文档；asr-backends 补上注册表的 size/sha256 字段与模型许可/体积表；phase0 补上 RTF 口径
说明（llama-cli 的 0.19 与程序内的 0.56）；phase2 补上「流式 ONNX 走另一条分支」的说明。

apps/gui/main.cpp

@@ -95,7 +95,7 @@ int main(int argc, char ** argv)
     parser.addOption(QCommandLineOption("screenshot-delay", "截图前等待秒数", "sec", "6"));
     parser.addOption(QCommandLineOption("no-tray", "不创建托盘图标（测试用）"));
     parser.addOption(QCommandLineOption("screenshot-settings", "打开设置对话框截图后退出", "path"));
-    parser.addOption(QCommandLineOption("settings-autoclose", "复现用：自动关闭设置对话框（reject|close|accept|ok）", "how"));
+    parser.addOption(QCommandLineOption("settings-autoclose", "复现用：自动操作设置对话框（reject|close|accept|ok|apply）", "how"));
     parser.addOption(QCommandLineOption("quit-after", "运行若干秒后优雅退出（测试退出路径用）", "sec"));
     parser.process(app);