docs: dashboard screenshot hero + collapsible bun-install

- Add a real screenshot of the redesigned dashboard (assets/dashboard.png) as a hero in
  all three READMEs and on the docs homepage (Astro optimizes it to a 35kB webp).
- Add a collapsible "Don't have bun? install it first" <details> next to the install
  command in each README (macOS/Linux + Windows scripts), since the ocx bin is bun-native.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: lidge-jun

README.ko.md

@@ -15,6 +15,10 @@
 
 </div>
 
+<p align="center">
+  <img src="assets/dashboard.png" alt="opencodex 대시보드 — 프록시 상태·프로바이더·모델을 보여주는 다크 컨트롤 패널" width="820">
+</p>
+
 Codex는 오직 Responses API(`/v1/responses`)만 사용합니다. opencodex는 Codex와 여러분의 LLM
 프로바이더 사이에 위치하여, 프로토콜을 실시간으로 변환합니다 — streaming, tool 호출, reasoning, 이미지까지
 모두 포함해서 — 양방향으로 동작합니다.
@@ -42,6 +46,23 @@ ocx start
 codex "Write a hello world in Rust"
 ```
 
+<details>
+<summary><b><a href="https://bun.sh">bun</a>이 없으신가요?</b> — 먼저 설치하세요 (opencodex는 bun에서 실행됩니다)</summary>
+
+<br/>
+
+```bash
+# macOS / Linux / WSL
+curl -fsSL https://bun.sh/install | bash
+
+# Windows (PowerShell)
+powershell -c "irm bun.sh/install.ps1 | iex"
+```
+
+설치 후 `bun install -g opencodex`를 다시 실행하세요. (`ocx` 바이너리는 bun 기반이라 bun이 `PATH`에 있어야 합니다.)
+
+</details>
+
 `provider/model` 형식으로 라우팅된 특정 모델을 지정할 수 있습니다:
 
 ```bash

README.md

@@ -15,6 +15,10 @@
 
 </div>
 
+<p align="center">
+  <img src="assets/dashboard.png" alt="opencodex dashboard — a dark provider control panel showing live proxy status, routed providers, and available models" width="820">
+</p>
+
 Codex only speaks the Responses API (`/v1/responses`). opencodex sits between Codex and your LLM
 provider, translating the protocol on the fly — streaming, tool calls, reasoning, and images included
 — in both directions.
@@ -42,6 +46,23 @@ ocx start
 codex "Write a hello world in Rust"
 ```
 
+<details>
+<summary><b>Don't have <a href="https://bun.sh">bun</a>?</b> — install it first (opencodex runs on bun)</summary>
+
+<br/>
+
+```bash
+# macOS / Linux / WSL
+curl -fsSL https://bun.sh/install | bash
+
+# Windows (PowerShell)
+powershell -c "irm bun.sh/install.ps1 | iex"
+```
+
+Then re-run `bun install -g opencodex`. (The `ocx` binary is bun-native, so bun must be on your `PATH`.)
+
+</details>
+
 Target a specific routed model with the `provider/model` form:
 
 ```bash

README.zh-CN.md

@@ -15,6 +15,10 @@
 
 </div>
 
+<p align="center">
+  <img src="assets/dashboard.png" alt="opencodex 控制台 —— 展示代理状态、provider 与可用模型的深色控制面板" width="820">
+</p>
+
 Codex 只能使用 Responses API（`/v1/responses`）。opencodex 位于 Codex 与你的 LLM
 provider 之间，实时翻译两者之间的协议 —— 包括 streaming、工具调用、推理（reasoning）和图像
 —— 并且是双向的。
@@ -42,6 +46,23 @@ ocx start
 codex "Write a hello world in Rust"
 ```
 
+<details>
+<summary><b>没有 <a href="https://bun.sh">bun</a>？</b> —— 先安装它（opencodex 运行在 bun 上）</summary>
+
+<br/>
+
+```bash
+# macOS / Linux / WSL
+curl -fsSL https://bun.sh/install | bash
+
+# Windows (PowerShell)
+powershell -c "irm bun.sh/install.ps1 | iex"
+```
+
+然后重新运行 `bun install -g opencodex`。（`ocx` 可执行文件是 bun 原生的，因此 bun 必须在你的 `PATH` 中。）
+
+</details>
+
 使用 `provider/model` 形式指定一个具体的已路由模型：
 
 ```bash

assets/dashboard.png

@@ -32,6 +32,8 @@ Codex CLI / App / SDK ──/v1/responses──▶ opencodex ──▶ Any provi
                   OpenRouter · Azure · DeepSeek · GLM · …and OpenAI itself
 ```
 
+![The opencodex dashboard — a dark provider control panel showing live proxy status, routed providers, and available models](../../assets/dashboard.png)
+
 <CardGrid stagger>
   <Card title="Any provider" icon="puzzle">
     Five adapters cover Anthropic Messages, Google Gemini, Azure, the OpenAI Responses passthrough,