v0.1.19 - Throughput overview & responsive header

- Throughput: new "Throughput Overview" header with Gauge icon and brand-green
  badge icons on each card (Today, This week, 4-week average, Horse Mix, Grain Mix)
- Throughput: inline rolling-range selector (7d / 4w / 6w / 12w, default 4 weeks)
  driving the customer-mix cards; stats window widened to 12 weeks so switching
  range is a pure client-side re-filter
- Throughput: cards collapse to a single even 5-across row on laptop and up,
  with container-query value text that scales to each card's width
- Throughput: date logic pinned to Australian Eastern time (fixes the day-early
  date); This week subtitle shows the Mon-Sun date range
- Throughput: subtler tinted add-form; removed the inline-entry kicker and the
  "Open full form" link
- Topbar: fix cramped laptop header - action toggles no longer wrap above the
  user button; search drops to its own row earlier

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/pyproject.toml

@@ -4,11 +4,12 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "data-entry-app-backend"
-version = "0.1.14"
+version = "0.1.19"
 description = "Costing platform MVP backend"
 requires-python = ">=3.11"
 dependencies = [
   "fastapi>=0.115,<1.0",
+  "python-multipart>=0.0.9,<1.0",
   "openpyxl>=3.1,<4.0",
   "rich>=13.9,<15.0",
   "uvicorn[standard]>=0.30,<1.0",