chore(release): 版本号 bump 到 1.0.3

1.0.x 发布线的第二个 patch。SDKCompatibleVersion 保持 1.0.0：
本次是纯内核修复，ProtocolVersion 未变，1.0.0 编出的 plugin.bin 无需重编。

跳过 1.0.2：该号未曾发布也无 tag，留空以免与任何本地构建混淆。

README/README_EN 补 v1.0.3 条目并把安装包文件名示例更新到 1.0.3；
installer.nsi 的 PRODUCT_VERSION 缺省值同步（正式构建仍由
makensis -DPRODUCT_VERSION 注入，这里只是本地手工构建的兜底）。

README_EN.md

@@ -179,6 +179,8 @@ External plugin development: see [homeagent-sdk](https://gitcode.com/JianFeeeee/
 
 ## Project Status
 
+**v1.0.3** — Kernel stage-coordinator double-unlock fix. The production `homed` main process once died outright with `fatal error: sync: unlock of unlocked mutex`, taking all 27 subprocess plugins with it: `Host.endStage` performed "decrement inflight, decide whether I'm the last leaver" *outside* the `coordMu` critical section while detaching the coordinator *inside* it, so a late-arriving plugin could attach to a coordinator that was already finishing, be misjudged as the last leaver, and unlock the same `stageMu` twice. **A `sync.Mutex` double unlock is a runtime fatal, not a panic, so the two layers of `recover` structurally cannot catch it**—which is exactly why the "a crashing plugin must not take down the kernel" isolation design failed wholesale here. The fix folds counting, decision, and detach into one critical section, and also moves the first arriver's `enter()` (which writes the shared segment) inside the lock—previously a late arriver could read a half-written segment. Ships with 5 regression cases, including a reverse check that stashes the old implementation back to confirm the tests really do reproduce the fatal.
+
 **v1.0.1** — Multimodal bugfix. The plugin ABI/protocol is unchanged, so `plugin.bin` artifacts built for 1.0.0 need no rebuild. Three defects fixed: (1) **vision silently failing**—media blocks attached to a tool message are not treated as viewable content by the model (measured on one image: 0/3 read from a tool message, 3/3 from a standalone user message); media now rides its own user message placed immediately after, which is what the plugin's own wording ("injected into the following conversation") always claimed; (2) **new multimodal capability declaration + fallback chain**—`core.llm.sources.<name>.vision/.audio` declares whether a source can genuinely process media (a gateway may strip `image_url` and still return 200, with identical prompt_tokens with and without the image); when it cannot, media is transcribed to text via a vision-capable source, finally wiring up the long-registered but never-read `core.input_processing.image.fallback_provider` settings; (3) **`see_video` frame-count semantics were inverted**—`fps=1/N` is a *rate*, not a count, so a 20s video yielded 2 frames when 10 were requested and 20 frames when 1 was requested; now `ffprobe` measures duration and the filter becomes `fps=N/duration` with `-frames:v` as a hard cap.
 
 **v1.0.0** — External plugins moved from C ABI shared libraries to **subprocess + shared memory**. The first release that no longer loads `.so`/`.dll`, and it is incompatible with 0.9.x (existing plugins must be rebuilt into `plugin.bin` with the new `plugindev`, though **business code needs zero changes**). Eliminates 6 classes of defects that had caused production incidents: hot-reload silently failing (`DF_1_NODELETE` making `dlclose` a no-op), no crash isolation (a plugin panic took down homed), stage lost updates (35.8~36.8% loss under the copy model), uncancellable cgo timeouts (linear OS-thread leaks), `output_send` reporting false success (the model was told "sent" while the message never went out), and Windows capability degradation (only 3 stage fields visible, no write-back). Three communication planes: stdio JSON-RPC (control) + shared memory segment (data) + event ring (notification); the privilege gradient is now enforced by three explicit gates. RPC round-trip p50 24.1µs; crash-to-recovery under 1s.
@@ -206,7 +208,7 @@ External plugin development: see [homeagent-sdk](https://gitcode.com/JianFeeeee/
 | **client** | waiter + desktop GUI | Connecting to a remote HomeAgent |
 
 - Linux: `.deb` (amd64/arm64), `.rpm` (x86_64), `.tar.gz`
-- Windows: `HomeAgent_v1.0.1_{Full,Server,Client}_win64.exe` (NSIS installer)
+- Windows: `HomeAgent_v1.0.3_{Full,Server,Client}_win64.exe` (NSIS installer)
 - Portable: `homeagent-bin-<os>_<arch>.tar.gz` (homed/waiter/initconfig)
 - Verification: `SHA256SUMS`