docs(frontend): rewrite README for multi-page Vue 3 layout

Reflects the current state — embedded build, per-route HTML entries,
ESLint 10 flat config, src/ layout, and the steps to add a new page.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/README.md

@@ -1,24 +1,24 @@
 # 3x-ui frontend
 
-Vue 3 + Ant Design Vue 4 + Vite. Builds into `../web/dist/`, which the
-Go binary will embed via `embed.FS` once the migration reaches the page
-handlers (Phase 4+).
-
-This directory exists alongside the legacy `web/html/` Vue 2 templates
-during the migration. Pages will move over one at a time on the
-`vue3-migration` branch.
+Vue 3 + Ant Design Vue 4 + Vite. Multi-page app — one HTML entry per
+panel route — built into `../web/dist/` and embedded into the Go binary
+via `embed.FS`.
 
 ## Dev
 
 ```sh
-cd frontend
 npm install
 npm run dev
 ```
 
-The dev server runs on `http://localhost:5173/` and proxies API calls to
-the Go panel at `http://localhost:2053/` — start the Go panel first
-(`go run main.go`), then start Vite.
+Vite serves on `http://localhost:5173/`. API calls and `/panel/*` routes
+proxy to the Go panel at `http://localhost:2053/`, so start the Go panel
+first (`go run main.go`) and then Vite.
+
+The proxy auto-rewrites `/panel`, `/panel/settings`, `/panel/inbounds`,
+`/panel/xray` to the matching Vite-served HTML in dev mode (see
+`MIGRATED_ROUTES` in `vite.config.js`), so the sidebar's
+production-style links work without round-tripping through Go.
 
 ## Production build
 
@@ -26,18 +26,50 @@ the Go panel at `http://localhost:2053/` — start the Go panel first
 npm run build
 ```
 
-Outputs to `../web/dist/`. The Go binary picks it up at compile time via
-`embed.FS`.
+Outputs to `../web/dist/` (HTML at the root, hashed JS/CSS under
+`assets/`). The Go binary embeds this directory at compile time and
+`web/controller/dist.go` serves the per-page HTML.
 
-## Where things live
+## Lint
 
-- `src/main.js` — app entrypoint (createApp, install Antd, mount)
-- `src/App.vue` — root component (currently a smoke-test placeholder)
-- `vite.config.js` — build + dev-server config
-- `index.html` — Vite HTML template
+```sh
+npm run lint
+```
 
-## Adding new pages
+ESLint 10 with `eslint.config.js` (flat config) — `vue3-recommended`
+plus a few rule overrides for the project's formatting style.
 
-For each legacy page being migrated, add an entry to
-`vite.config.js` `rollupOptions.input`. Each entry produces its own
-HTML file in `web/dist/`, which the Go panel route handler will serve.
+## Layout
+
+```
+frontend/
+├── *.html                 # Vite entry HTML, one per panel route
+├── eslint.config.js
+├── vite.config.js
+└── src/
+    ├── entries/           # Per-page bootstrap (createApp + mount)
+    ├── pages/             # One folder per route, each with the page
+    │   ├── index/         # component + helpers + sub-components
+    │   ├── login/
+    │   ├── inbounds/
+    │   ├── xray/
+    │   ├── settings/
+    │   └── sub/
+    ├── components/        # Cross-page Vue components
+    ├── composables/       # Reusable reactive logic (useTheme, …)
+    ├── api/               # Axios setup, CSRF interceptor
+    ├── i18n/              # vue-i18n init (locales live in web/translation/)
+    ├── models/            # Inbound, Outbound, Status, … domain classes
+    └── utils/             # HttpUtil, ObjectUtil, LanguageManager, …
+```
+
+## Adding a new page
+
+1. Add `frontend/<page>.html` referencing `/src/entries/<page>.js`.
+2. Add `src/entries/<page>.js` that imports the page component and
+   mounts it.
+3. Add the page component under `src/pages/<page>/`.
+4. Register the entry in `rollupOptions.input` in `vite.config.js`.
+5. If the page is reachable from the sidebar at `/panel/<route>`, add
+   it to `MIGRATED_ROUTES` so the dev proxy serves the Vite HTML.
+6. Wire the Go controller to `serveDistPage(c, "<page>.html")`.