Remove the UnitGrid experiment slide (unused)

Drops the standalone "Who gets hurt — by severity" slide and the
`UnitGrid.vue` canvas component it was the sole consumer of. Both remain
recoverable from history (`9f22aea`, `746c4f2`) if we revisit the unit-chart
idea. `PersonIcon.vue` stays — slide 4's road-user selector still uses it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: ryan-williams

components/UnitGrid.vue

@@ -721,194 +721,3 @@ class: thanks
 [ryanw@hudcostreets.org] · [hudcostreets.org](https://hudcostreets.org) · [@hudcostreets](https://instagram.com/hudcostreets)
 
 Slides + source: [safe26.hccs.dev](https://safe26.hccs.dev)
-
----
-class: unitgrid-exp
-clicks: 0
----
-
-<script setup>
-import { computed, ref } from 'vue'
-
-// Full-year (annualized) figures; the YTD toggle prorates these to today.
-const KSI = {
-  killed:   { driver: 301,   passenger: 92,    pedestrian: 173,  cyclist: 16   },
-  serious:  { driver: 1977,  passenger: 1001,  pedestrian: 703,  cyclist: 257  },
-  moderate: { driver: 21249, passenger: 9545,  pedestrian: 1840, cyclist: 1256 },
-  minor:    { driver: 26441, passenger: 12624, pedestrian: 1539, cyclist: 800  },
-}
-const TYPES = ['driver', 'passenger', 'pedestrian', 'cyclist']
-const TYPE_LABELS = { driver: 'Driver', passenger: 'Passenger', pedestrian: 'Ped', cyclist: 'Cyclist' }
-const COLORS = { driver: '#a94c9a', passenger: '#f08030', pedestrian: '#d85a6a', cyclist: '#7c5295' }
-const ROWS = [
-  { key: 'killed',   label: 'Killed' },
-  { key: 'serious',  label: 'Serious injury' },
-  { key: 'moderate', label: 'Moderate' },
-  { key: 'minor',    label: 'Minor / other' },
-]
-
-// Fraction of the calendar year elapsed (uniform proration).
-const now = new Date()
-const yStart = new Date(now.getFullYear(), 0, 1)
-const yEnd = new Date(now.getFullYear() + 1, 0, 1)
-const yearFrac = (now - yStart) / (yEnd - yStart)
-const asOf = now.toLocaleDateString('en-US', { month: 'short', day: 'numeric' })
-
-const ytd = ref(false)
-const factor = computed(() => ytd.value ? yearFrac : 1)
-const scaledCounts = (key) => {
-  const f = factor.value
-  return Object.fromEntries(TYPES.map(t => [t, KSI[key][t] * f]))
-}
-
-const selected = ref([...TYPES])
-const allSelected = () => TYPES.every(t => selected.value.includes(t))
-const isSel = (t) => selected.value.includes(t)
-function selectAll() { selected.value = [...TYPES] }
-function clickType(t) {
-  if (allSelected()) { selected.value = [t]; return }
-  const s = new Set(selected.value)
-  s.has(t) ? s.delete(t) : s.add(t)
-  if (s.size === 0 || s.size === TYPES.length) selectAll()
-  else selected.value = TYPES.filter(x => s.has(x))
-}
-const rowTotal = (key) => Math.round(selected.value.reduce((sum, t) => sum + KSI[key][t], 0) * factor.value)
-</script>
-
-<div class="exp-head">
-  <h1>Who gets hurt — by severity <span class="exp-tag">experiment</span></h1>
-  <div class="scope-toggle">
-    <button :class="{ active: !ytd }" @mousedown.prevent @click="ytd = false">Annual</button>
-    <button :class="{ active: ytd }" @mousedown.prevent @click="ytd = true">YTD · {{ asOf }}</button>
-  </div>
-</div>
-
-<div class="rows">
-  <div class="urow" v-for="row in ROWS" :key="row.key">
-    <div class="meta">
-      <span class="n">{{ rowTotal(row.key).toLocaleString() }}</span>
-      <span class="lab">{{ row.label }}</span>
-    </div>
-    <div class="box">
-      <UnitGrid :counts="scaledCounts(row.key)" :colors="COLORS" :types="TYPES" :selected="selected" />
-    </div>
-  </div>
-</div>
-
-<div class="vt-select">
-  <button :class="{ active: allSelected() }" @mousedown.prevent @click="selectAll">All</button>
-  <button
-    v-for="t in TYPES"
-    :key="t"
-    :class="[t, { active: isSel(t) && !allSelected() }]"
-    :title="TYPE_LABELS[t]"
-    @mousedown.prevent
-    @click="clickType(t)"
-  ><PersonIcon :type="t" /></button>
-</div>
-
-<style>
-.slidev-layout.unitgrid-exp {
-  padding: 1rem 2rem 0.8rem;
-  display: flex;
-  flex-direction: column;
-  .exp-head {
-    display: flex;
-    align-items: center;
-    justify-content: space-between;
-    gap: 1rem;
-    margin-bottom: 0.6rem;
-  }
-  h1 { font-size: 1.8rem; font-weight: 600; margin: 0; }
-  .exp-tag {
-    font-size: 0.8rem;
-    font-weight: 400;
-    opacity: 0.6;
-    border: 1px solid rgba(255,255,255,0.4);
-    border-radius: 999px;
-    padding: 0.1rem 0.5rem;
-    vertical-align: middle;
-  }
-  .scope-toggle {
-    display: inline-flex;
-    flex: 0 0 auto;
-    border: 1px solid rgba(255,255,255,0.4);
-    border-radius: 999px;
-    overflow: hidden;
-    button {
-      font-family: inherit;
-      font-size: 0.85rem;
-      padding: 0.25rem 0.9rem;
-      background: transparent;
-      color: rgba(255,255,255,0.8);
-      border: none;
-      cursor: pointer;
-      white-space: nowrap;
-    }
-    button.active { background: var(--hccs-accent); color: #14401f; font-weight: 600; }
-  }
-  .rows {
-    flex: 1 1 auto;
-    display: grid;
-    grid-template-rows: repeat(4, 1fr);
-    gap: 0.7rem;
-    min-height: 0;
-  }
-  .urow {
-    display: grid;
-    grid-template-columns: 9rem 1fr;
-    align-items: center;
-    gap: 0.8rem;
-    min-height: 0;
-  }
-  .meta {
-    display: flex;
-    flex-direction: column;
-    align-items: flex-end;
-    line-height: 1.05;
-  }
-  .meta .n { font-size: 1.5rem; font-weight: 700; color: var(--hccs-accent); font-variant-numeric: tabular-nums; }
-  .meta .lab { font-size: 0.95rem; opacity: 0.9; }
-  .box {
-    height: 100%;
-    min-height: 0;
-    background: rgba(0,0,0,0.13);
-    border-radius: 4px;
-  }
-  .vt-select {
-    display: flex;
-    flex-wrap: wrap;
-    justify-content: center;
-    align-items: center;
-    gap: 0.4rem;
-    margin-top: 0.7rem;
-    button {
-      display: inline-flex;
-      align-items: center;
-      justify-content: center;
-      font-size: 0.85rem;
-      padding: 0.2rem 0.55rem;
-      border-radius: 999px;
-      border: 1px solid rgba(255,255,255,0.55);
-      background: rgba(255,255,255,0.92);
-      color: #14401f;
-      cursor: pointer;
-      font-family: inherit;
-      white-space: nowrap;
-    }
-    button .person-icon { width: 1.35em; height: 1.35em; }
-    button.active { background: var(--hccs-accent); color: #14401f; border-color: var(--hccs-accent); font-weight: 600; }
-    button.driver     .person-icon { color: #a94c9a; }
-    button.passenger  .person-icon { color: #f08030; }
-    button.pedestrian .person-icon { color: #d85a6a; }
-    button.cyclist    .person-icon { color: #7c5295; }
-    button.driver.active     { background: #a94c9a; border-color: #a94c9a; color: #fff; }
-    button.passenger.active  { background: #f08030; border-color: #f08030; color: #14401f; }
-    button.pedestrian.active { background: #d85a6a; border-color: #d85a6a; color: #fff; }
-    button.cyclist.active    { background: #7c5295; border-color: #7c5295; color: #fff; }
-    button.active .person-icon { color: inherit; }
-  }
-}
-</style>
-
-[ryanw@hudcostreets.org]: mailto:ryanw@hudcostreets.org