feat: persistent sessions support, remove track_map, add characteristics + tracks views

- Remove obsolete track_map use case from types, views, and router
- Delete TrackMapView.vue (superseded by persistent TrackDetailView)
- Auto-analyze in handleBuildTrack before building track model
- Add CharacteristicsView: expandable car cards with aggregated shift-point
  profiles (gear RPM/speed ranges, recommended shift RPM)
- Add TracksView + TrackDetailView + tracks Pinia store (Canvas 2D geometry)
- Add characteristics API client functions (listCarProfiles)
- Add tracks and characteristics nav items and routes
- Update Game type values to match backend snake_case (project_cars_1/2)
- Update use_case types and labels (remove track_map, keep track_mapping)

src/views/TracksView.vue

@@ -0,0 +1,116 @@
+<script setup lang="ts">
+import { onMounted } from 'vue'
+import { RouterLink } from 'vue-router'
+import { useTracksStore } from '@/stores/tracks'
+
+const store = useTracksStore()
+
+onMounted(() => {
+  store.fetchTracks()
+})
+
+function formatTime(iso: string): string {
+  return new Date(iso).toLocaleString()
+}
+
+function gameLabel(game: string): string {
+  const labels: Record<string, string> = {
+    assetto_corsa: 'Assetto Corsa',
+    assetto_corsa_competizione: 'ACC',
+    project_cars_1: 'Project CARS 1',
+    project_cars_2: 'Project CARS 2',
+  }
+  return labels[game] ?? game
+}
+
+async function handleDelete(game: string, trackName: string) {
+  if (confirm(`Delete track model "${trackName}" (${gameLabel(game)})?`)) {
+    await store.deleteTrack(game, trackName)
+  }
+}
+</script>
+
+<template>
+  <div class="tracks-view">
+    <div class="flex items-center justify-between mb-3">
+      <h2 class="page-title">Tracks</h2>
+      <RouterLink to="/sessions" class="btn btn-secondary">
+        + Map a Track
+      </RouterLink>
+    </div>
+
+    <div v-if="store.error" class="card mb-3 text-error">{{ store.error }}</div>
+    <div v-if="store.loading && store.tracks.length === 0" class="card text-secondary">Loading tracks...</div>
+
+    <div v-if="store.tracks.length === 0 && !store.loading" class="card text-secondary">
+      <p class="mb-2">No track models stored yet.</p>
+      <p style="font-size: 0.85rem; color: var(--color-text-muted)">
+        Create a Track Mapping session, record left and right boundary laps, then build the track model.
+      </p>
+    </div>
+
+    <div v-else class="track-cards">
+      <div v-for="track in store.tracks" :key="`${track.game}-${track.track_name}`" class="card track-card">
+        <div class="flex items-center justify-between mb-1">
+          <div class="flex items-center gap-2">
+            <span class="badge badge-primary">{{ gameLabel(track.game) }}</span>
+            <span class="track-name">{{ track.track_name }}</span>
+          </div>
+          <div class="flex gap-1">
+            <RouterLink
+              :to="`/tracks/${track.game}/${track.track_name}`"
+              class="btn btn-secondary btn-sm"
+            >
+              View
+            </RouterLink>
+            <button
+              class="btn btn-danger btn-sm"
+              @click="handleDelete(track.game, track.track_name)"
+            >
+              Delete
+            </button>
+          </div>
+        </div>
+        <div class="track-meta">
+          <span class="text-secondary">{{ track.corner_count }} corners</span>
+          <span class="text-muted">·</span>
+          <span class="text-muted" style="font-size: 0.8rem">{{ formatTime(track.created_at) }}</span>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.page-title {
+  font-size: 1.5rem;
+  margin: 0;
+}
+
+.track-cards {
+  display: flex;
+  flex-direction: column;
+  gap: 0.75rem;
+}
+
+.track-card {
+  transition: border-color 0.15s ease;
+}
+
+.track-card:hover {
+  border-color: var(--color-primary);
+}
+
+.track-name {
+  font-weight: 600;
+  font-size: 1rem;
+}
+
+.track-meta {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  font-size: 0.85rem;
+  margin-top: 0.25rem;
+}
+</style>