feat: restructure router into /data/* /eval/* /train/* domains with backward-compat redirects

- Export named `routes` array from router/index.ts for testability
- Move label/fetch/corrections/imitate under /data/* namespace
- Move benchmark/compare under /eval/* namespace
- Add /train/jobs and /train/results under /train/* namespace
- Add / -> DashboardView and /fleet -> ModelsView (replaces old / -> LabelView)
- Add backward-compat redirects for all old flat paths (/benchmark, /models, /stats, /label, /fetch, /corrections, /imitate)
- Add stub views for DashboardView, CompareView, TrainJobsView, TrainResultsView (implemented in later tasks)
- Add router.test.ts: 16 tests covering route structure and redirect targets

web/src/router/index.ts

@@ -1,25 +1,49 @@
 import { createRouter, createWebHashHistory } from 'vue-router'
-import LabelView    from '../views/LabelView.vue'
 
-// Views are lazy-loaded to keep initial bundle small
-const FetchView     = () => import('../views/FetchView.vue')
-const StatsView     = () => import('../views/StatsView.vue')
-const BenchmarkView = () => import('../views/BenchmarkView.vue')
-const SettingsView    = () => import('../views/SettingsView.vue')
-const CorrectionsView = () => import('../views/CorrectionsView.vue')
-const ModelsView      = () => import('../views/ModelsView.vue')
-const ImitateView     = () => import('../views/ImitateView.vue')
+// Lazy-loaded views
+const DashboardView    = () => import('../views/DashboardView.vue')
+const LabelView        = () => import('../views/LabelView.vue')
+const FetchView        = () => import('../views/FetchView.vue')
+const CorrectionsView  = () => import('../views/CorrectionsView.vue')
+const ImitateView      = () => import('../views/ImitateView.vue')
+const BenchmarkView    = () => import('../views/BenchmarkView.vue')
+const CompareView      = () => import('../views/CompareView.vue')
+const TrainJobsView    = () => import('../views/TrainJobsView.vue')
+const TrainResultsView = () => import('../views/TrainResultsView.vue')
+const ModelsView       = () => import('../views/ModelsView.vue')
+const SettingsView     = () => import('../views/SettingsView.vue')
+
+export const routes = [
+  // ── Top-level ────────────────────────────────────────────
+  { path: '/',         component: DashboardView, meta: { title: 'Dashboard' } },
+  { path: '/fleet',    component: ModelsView,    meta: { title: 'Fleet'     } },
+  { path: '/settings', component: SettingsView,  meta: { title: 'Settings'  } },
+
+  // ── Data domain ──────────────────────────────────────────
+  { path: '/data/label',       component: LabelView,       meta: { title: 'Label'       } },
+  { path: '/data/fetch',       component: FetchView,       meta: { title: 'Fetch'       } },
+  { path: '/data/corrections', component: CorrectionsView, meta: { title: 'Corrections' } },
+  { path: '/data/imitate',     component: ImitateView,     meta: { title: 'Imitate'     } },
+
+  // ── Eval domain ──────────────────────────────────────────
+  { path: '/eval/benchmark', component: BenchmarkView, meta: { title: 'Benchmark' } },
+  { path: '/eval/compare',   component: CompareView,   meta: { title: 'Compare'   } },
+
+  // ── Train domain ─────────────────────────────────────────
+  { path: '/train/jobs',    component: TrainJobsView,    meta: { title: 'Training Jobs'    } },
+  { path: '/train/results', component: TrainResultsView, meta: { title: 'Training Results' } },
+
+  // ── Backward-compat redirects ────────────────────────────
+  { path: '/benchmark',   redirect: '/eval/benchmark'   },
+  { path: '/models',      redirect: '/fleet'            },
+  { path: '/stats',       redirect: '/'                 },
+  { path: '/label',       redirect: '/data/label'       },
+  { path: '/fetch',       redirect: '/data/fetch'       },
+  { path: '/corrections', redirect: '/data/corrections' },
+  { path: '/imitate',     redirect: '/data/imitate'     },
+]
 
 export const router = createRouter({
   history: createWebHashHistory(),
-  routes: [
-    { path: '/',            component: LabelView,       meta: { title: 'Label' } },
-    { path: '/fetch',       component: FetchView,       meta: { title: 'Fetch' } },
-    { path: '/stats',       component: StatsView,       meta: { title: 'Stats' } },
-    { path: '/benchmark',   component: BenchmarkView,   meta: { title: 'Benchmark' } },
-    { path: '/models',      component: ModelsView,      meta: { title: 'Models' } },
-    { path: '/imitate',     component: ImitateView,     meta: { title: 'Imitate' }     },
-    { path: '/corrections', component: CorrectionsView, meta: { title: 'Corrections' } },
-    { path: '/settings',    component: SettingsView,    meta: { title: 'Settings' } },
-  ],
+  routes,
 })

web/src/router/router.test.ts

@@ -0,0 +1,94 @@
+import { describe, it, expect } from 'vitest'
+import { createRouter, createWebHashHistory } from 'vue-router'
+
+// Import the raw routes array so we can test structure without mounting App
+import { routes } from './index'
+
+describe('router routes', () => {
+  it('exports a routes array', () => {
+    expect(Array.isArray(routes)).toBe(true)
+  })
+
+  it('has / pointing to DashboardView', () => {
+    const root = routes.find(r => r.path === '/')
+    expect(root).toBeDefined()
+    // Component should be async (lazy) or have a name
+    expect(root?.component).toBeDefined()
+  })
+
+  it('has /fleet route', () => {
+    const r = routes.find(r => r.path === '/fleet')
+    expect(r).toBeDefined()
+  })
+
+  it('has /data/label route', () => {
+    const r = routes.find(r => r.path === '/data/label')
+    expect(r).toBeDefined()
+  })
+
+  it('has /data/fetch route', () => {
+    const r = routes.find(r => r.path === '/data/fetch')
+    expect(r).toBeDefined()
+  })
+
+  it('has /data/corrections route', () => {
+    const r = routes.find(r => r.path === '/data/corrections')
+    expect(r).toBeDefined()
+  })
+
+  it('has /data/imitate route', () => {
+    const r = routes.find(r => r.path === '/data/imitate')
+    expect(r).toBeDefined()
+  })
+
+  it('has /eval/benchmark route', () => {
+    const r = routes.find(r => r.path === '/eval/benchmark')
+    expect(r).toBeDefined()
+  })
+
+  it('has /eval/compare route', () => {
+    const r = routes.find(r => r.path === '/eval/compare')
+    expect(r).toBeDefined()
+  })
+
+  it('has /train/jobs route', () => {
+    const r = routes.find(r => r.path === '/train/jobs')
+    expect(r).toBeDefined()
+  })
+
+  it('has /train/results route', () => {
+    const r = routes.find(r => r.path === '/train/results')
+    expect(r).toBeDefined()
+  })
+
+  it('has /settings route', () => {
+    const r = routes.find(r => r.path === '/settings')
+    expect(r).toBeDefined()
+  })
+
+  it('has backward-compat redirect from /benchmark to /eval/benchmark', () => {
+    const r = routes.find(r => r.path === '/benchmark')
+    expect(r).toBeDefined()
+    expect((r as { redirect?: string }).redirect).toBe('/eval/benchmark')
+  })
+
+  it('has backward-compat redirect from /models to /fleet', () => {
+    const r = routes.find(r => r.path === '/models')
+    expect(r).toBeDefined()
+    expect((r as { redirect?: string }).redirect).toBe('/fleet')
+  })
+
+  it('has backward-compat redirect from /stats to /', () => {
+    const r = routes.find(r => r.path === '/stats')
+    expect(r).toBeDefined()
+    expect((r as { redirect?: string }).redirect).toBe('/')
+  })
+
+  it('can create a functional router instance', () => {
+    const router = createRouter({
+      history: createWebHashHistory(),
+      routes,
+    })
+    expect(router).toBeDefined()
+  })
+})

web/src/views/CompareView.vue

@@ -0,0 +1,10 @@
+<template>
+  <div class="view-placeholder">
+    <h2>CompareView</h2>
+    <p>Coming soon.</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+// Stub — will be implemented in a later task
+</script>

web/src/views/DashboardView.vue

@@ -0,0 +1,10 @@
+<template>
+  <div class="view-placeholder">
+    <h2>DashboardView</h2>
+    <p>Coming soon.</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+// Stub — will be implemented in a later task
+</script>

web/src/views/TrainJobsView.vue

@@ -0,0 +1,10 @@
+<template>
+  <div class="view-placeholder">
+    <h2>TrainJobsView</h2>
+    <p>Coming soon.</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+// Stub — will be implemented in a later task
+</script>

web/src/views/TrainResultsView.vue

@@ -0,0 +1,10 @@
+<template>
+  <div class="view-placeholder">
+    <h2>TrainResultsView</h2>
+    <p>Coming soon.</p>
+  </div>
+</template>
+
+<script setup lang="ts">
+// Stub — will be implemented in a later task
+</script>