Add vue-router, login/setup flow and backend logging

Refactor frontend to route-based navigation with vue-router, add
system setup and login pages with API integration. Add structured
logging, access-log middleware and startup lifecycle to FastAPI
backend.

web/src/views/SetupRouteView.vue

@@ -0,0 +1,51 @@
+<template>
+  <SetupView
+    :initial-state="bootstrapState || {}"
+    :submitting="setupSubmitting"
+    :runtime-testing="runtimeTesting"
+    :database-testing="databaseTesting"
+    :runtime-test-passed="runtimeTestPassed"
+    :database-test-passed="databaseTestPassed"
+    :runtime-test-message="runtimeTestMessage"
+    :database-test-message="databaseTestMessage"
+    :error-message="setupError"
+    @submit="submitSetup"
+    @runtime-test="handleRuntimeTest"
+    @database-test="handleDatabaseTest"
+    @runtime-dirty="handleRuntimeDirty"
+    @database-dirty="handleDatabaseDirty"
+  />
+</template>
+
+<script setup>
+import { useRouter } from 'vue-router'
+
+import { useSystemState } from '../composables/useSystemState.js'
+import SetupView from './SetupView.vue'
+
+const router = useRouter()
+const {
+  bootstrapState,
+  databaseTestMessage,
+  databaseTestPassed,
+  databaseTesting,
+  handleDatabaseDirty,
+  handleDatabaseTest,
+  handleRuntimeDirty,
+  handleRuntimeTest,
+  handleSetupSubmit,
+  runtimeTestMessage,
+  runtimeTestPassed,
+  runtimeTesting,
+  setupError,
+  setupSubmitting
+} = useSystemState()
+
+async function submitSetup(payload) {
+  const completed = await handleSetupSubmit(payload)
+
+  if (completed) {
+    router.replace({ name: 'login' })
+  }
+}
+</script>