spa hardening, offline logging, rate limit fixes

server:
- backup exporter, auth extractors, error shapes, CONTEXT (prior work)
- spa assets served outside the rate limit via route_layer
- requests_per_second went to per_second(), which takes an interval not a
  rate: 50 meant one request per 50s once burst was spent. now converted
  properly. 15/s, burst 60

spa fixes:
- account delete cleared snake_case token keys that were never written
- refresh interceptor could retry forever
- date ranges used local day boundaries stamped +00:00
- "all" period trend plotted one page; calendar days fabricated mood 3
- chart grid invisible: hsl(var(--border)) against rgba tokens
- blob url leak, orphaned media on failed save, devtools in prod bundle
- pt-safe/safe-area-pb classes never existed

spa features:
- offline outbox: entries queue to IndexedDB, replay with backoff, only
  server refusals count against an entry
- drafts persist, quick-log sheet, diary infinite scroll + filters
- route error boundary, stale-chunk recovery, no service worker in dev

a11y + perf:
- mood picker is a radiogroup, activity picker keyboard-operable,
  text alternatives for colour/emoji, locale week start
- dark glass over the bright photo: worst case 1.4:1 -> 4.9-9.6:1
- initial payload 1095->769kB raw, 306->230kB gzip; 38 unused components
  and 5 deps dropped; fonts 218->133kB

53 tests added (43 spa, 10 server)

spa/vite.config.ts

@@ -4,9 +4,37 @@ import { TanStackRouterVite } from "@tanstack/router-plugin/vite"
 import viteReact from "@vitejs/plugin-react"
 import tailwindcss from "@tailwindcss/vite"
 
+/**
+ * The three dependencies every screen needs, each in one chunk. Left to itself
+ * the splitter emits dozens of sub-kilobyte files, where the request costs
+ * more than the code.
+ *
+ * Deliberately not a catch-all: a `node_modules` group would sweep the chart
+ * library and the date picker — which only two screens want — into a chunk
+ * that loads on first paint.
+ */
+const VENDOR_GROUPS = [
+  { name: "react", test: /node_modules[/\\](react|react-dom|scheduler)[/\\]/ },
+  { name: "base-ui", test: /node_modules[/\\]@base-ui[/\\]/ },
+  { name: "tanstack", test: /node_modules[/\\]@tanstack[/\\]/ },
+]
+
 const config = defineConfig({
   resolve: { tsconfigPaths: true },
   plugins: [devtools(), tailwindcss(), TanStackRouterVite(), viteReact()],
+  build: {
+    rolldownOptions: {
+      output: {
+        advancedChunks: {
+          minSize: 12_000,
+          groups: VENDOR_GROUPS.map((group, index) => ({
+            ...group,
+            priority: VENDOR_GROUPS.length - index,
+          })),
+        },
+      },
+    },
+  },
 })
 
 export default config