feat(v5): add Inertia app shell with Flux health

Adds v5 routing, middleware, home page rendering, team context sharing,
project model/table support, and Flux health reporting. Installs Flux in
container builds with role-aware s6 services and documents runtime roles.

resources/views/v5/app.blade.php

@@ -0,0 +1,18 @@
+<!DOCTYPE html>
+<html lang="{{ str_replace('_', '-', app()->getLocale()) }}">
+
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+    <meta name="csrf-token" content="{{ csrf_token() }}">
+    <title inertia>{{ config('app.name') }} v5</title>
+    @viteReactRefresh
+    @vite('resources/js/v5/app.jsx')
+    <x-inertia::head />
+</head>
+
+<body>
+    <x-inertia::app id="v5-app" />
+</body>
+
+</html>