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/app/db/migrations.py

@@ -129,6 +129,8 @@ _LEGACY_COLUMN_PATCHES: tuple[tuple[str, str, str], ...] = (
     ("production_throughput_entries", "for_stock", "BOOLEAN NOT NULL DEFAULT FALSE"),
     ("production_throughput_entries", "job_number", "VARCHAR(64)"),
     ("production_throughput_entries", "stock_quantity", "FLOAT"),
+    ("raw_materials", "rounding_decimals", "INTEGER NOT NULL DEFAULT 2"),
+    ("mix_calculator_session_lines", "rounding_decimals", "INTEGER NOT NULL DEFAULT 2"),
 )