feat: add 24h cache freshness with auto-refresh on search

- part_scraper_service.ts: new CACHE_TTL_HOURS (24), isCategoryStale()
  checks the most recent scrapedAt for a given ComponentType's mapped
  category, ensureFreshCategory() re-scrapes it synchronously if missing
  or stale (errors are logged, not thrown, so search still falls back to
  whatever is already cached)
- ScrapedPartsController#index: when a typeId filter is provided, the
  corresponding category cache is refreshed eagerly if stale before
  querying results. Free-text searches without a typeId skip this to
  avoid re-scraping every mapped category on every keystroke -
  'node ace scrape:parts' still refreshes everything at once on demand
- 4 new tests covering staleness detection (missing cache, <24h, >24h)
  and that unmapped types never trigger a scrape/network call

tests/functional/scraped_parts.spec.ts

@@ -3,6 +3,11 @@ import { DateTime } from 'luxon'
 import User from '#models/user'
 import ComponentType from '#models/component_type'
 import ScrapedPart from '#models/scraped_part'
+import {
+  isCategoryStale,
+  ensureFreshCategory,
+  CACHE_TTL_HOURS,
+} from '#services/part_scraper_service'
 
 async function createUser(email: string) {
   return User.create({
@@ -68,3 +73,53 @@ test.group('Scraped parts search', () => {
     response.assertRedirectsTo('/auth/login')
   })
 })
+
+test.group('Scraped parts 24h cache freshness', () => {
+  test('a category with no cached parts is considered stale', async ({ assert }) => {
+    const type = await createType('Processor-freshness-1')
+
+    assert.isTrue(await isCategoryStale(type))
+  })
+
+  test('a category scraped within the last 24h is not stale', async ({ assert }) => {
+    const type = await createType('Processor-freshness-2')
+    await ScrapedPart.create({
+      typeId: type.id,
+      name: 'ZZZ-Test-Fresh Part',
+      price: 100,
+      imageUrl: null,
+      source: 'pc-builder.io',
+      sourceUrl: 'https://fr.pc-builder.io/cpu/fresh-part',
+      sourceRef: 'fresh-part-ref',
+      scrapedAt: DateTime.now().minus({ hours: 1 }),
+    })
+
+    assert.isFalse(await isCategoryStale(type))
+  })
+
+  test('a category scraped more than 24h ago is stale', async ({ assert }) => {
+    const type = await createType('Processor-freshness-3')
+    await ScrapedPart.create({
+      typeId: type.id,
+      name: 'ZZZ-Test-Stale Part',
+      price: 100,
+      imageUrl: null,
+      source: 'pc-builder.io',
+      sourceUrl: 'https://fr.pc-builder.io/cpu/stale-part',
+      sourceRef: 'stale-part-ref',
+      scrapedAt: DateTime.now().minus({ hours: CACHE_TTL_HOURS + 1 }),
+    })
+
+    assert.isTrue(await isCategoryStale(type))
+  })
+
+  test('ensureFreshCategory does not scrape unmapped types (no network call)', async ({
+    assert,
+  }) => {
+    // "Other" is a real, unmapped ComponentType (see CATEGORY_SLUGS): this
+    // must resolve without making any outbound HTTP request.
+    const type = await createType('Other-freshness-unmapped', false)
+
+    await assert.doesNotReject(() => ensureFreshCategory(type))
+  })
+})