Implement performance improvements across backend and frontend

- models.py: add composite (user_id, date) indexes to flock_history,
  feed_purchases, and other_purchases for faster date-filtered queries
  (egg_collections already had one via its unique constraint)
- main.py: add v2.2 migration to create the three composite indexes on
  existing installs at startup
- stats.py: fix N+1 query in monthly_stats — flock history is now fetched
  once and looked up per month using bisect_right instead of one DB query
  per month row; also remove unnecessary Decimal(str(...)) round-trips
  since SQLAlchemy already returns Numeric columns as Decimal
- eggs.py: add limit parameter (default 500, max 1000) to list_eggs to
  cap unbounded fetches on large datasets
- dashboard.js: pass start= (30 days ago) when fetching eggs so the
  dashboard only loads the data it actually needs for the chart and
  recent collections list

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/main.py

@@ -79,6 +79,18 @@ def _run_migrations():
         except Exception:
             db.rollback()  # column already exists — safe to ignore
 
+        # v2.2 — composite (user_id, date) indexes for faster filtered queries
+        for sql in [
+            "CREATE INDEX ix_flock_history_user_date  ON flock_history  (user_id, date)",
+            "CREATE INDEX ix_feed_purchases_user_date  ON feed_purchases  (user_id, date)",
+            "CREATE INDEX ix_other_purchases_user_date ON other_purchases (user_id, date)",
+        ]:
+            try:
+                db.execute(text(sql))
+                db.commit()
+            except Exception:
+                db.rollback()  # index already exists — safe to ignore
+
 
 @asynccontextmanager
 async def lifespan(app: FastAPI):

backend/models.py

@@ -1,5 +1,5 @@
 from datetime import date, datetime
-from sqlalchemy import Boolean, Integer, Date, DateTime, Text, Numeric, String, ForeignKey, UniqueConstraint, func
+from sqlalchemy import Boolean, Integer, Date, DateTime, Text, Numeric, String, ForeignKey, UniqueConstraint, Index, func
 from sqlalchemy.orm import Mapped, mapped_column
 from database import Base
 
@@ -30,6 +30,7 @@ class EggCollection(Base):
 
 class FlockHistory(Base):
     __tablename__ = "flock_history"
+    __table_args__ = (Index("ix_flock_history_user_date", "user_id", "date"),)
 
     id:            Mapped[int]      = mapped_column(Integer, primary_key=True, autoincrement=True)
     user_id:       Mapped[int]      = mapped_column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
@@ -41,6 +42,7 @@ class FlockHistory(Base):
 
 class FeedPurchase(Base):
     __tablename__ = "feed_purchases"
+    __table_args__ = (Index("ix_feed_purchases_user_date", "user_id", "date"),)
 
     id:            Mapped[int]      = mapped_column(Integer, primary_key=True, autoincrement=True)
     user_id:       Mapped[int]      = mapped_column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)
@@ -53,6 +55,7 @@ class FeedPurchase(Base):
 
 class OtherPurchase(Base):
     __tablename__ = "other_purchases"
+    __table_args__ = (Index("ix_other_purchases_user_date", "user_id", "date"),)
 
     id:         Mapped[int]      = mapped_column(Integer, primary_key=True, autoincrement=True)
     user_id:    Mapped[int]      = mapped_column(Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True)

backend/routers/eggs.py

@@ -17,13 +17,16 @@ router = APIRouter(prefix="/api/eggs", tags=["eggs"])
 def list_eggs(
     start: Optional[date] = None,
     end:   Optional[date] = None,
+    limit: int = 500,
     db:    Session = Depends(get_db),
     current_user: User = Depends(get_current_user),
 ):
+    limit = min(limit, 1000)
     q = (
         select(EggCollection)
         .where(EggCollection.user_id == current_user.id)
         .order_by(EggCollection.date.desc())
+        .limit(limit)
     )
     if start:
         q = q.where(EggCollection.date >= start)

backend/routers/stats.py

@@ -1,4 +1,5 @@
 import calendar
+from bisect import bisect_right
 from datetime import date, datetime, timedelta
 from decimal import Decimal
 from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
@@ -170,20 +171,24 @@ def monthly_stats(
 
     other_map = {(r.year, r.month): r.other_cost for r in other_rows}
 
+    # Fetch all flock history once (ascending) to avoid N+1 per month
+    flock_all = db.scalars(
+        select(FlockHistory)
+        .where(FlockHistory.user_id == uid)
+        .order_by(FlockHistory.date)
+    ).all()
+    flock_dates  = [f.date for f in flock_all]
+    flock_counts = [f.chicken_count for f in flock_all]
+
+    def flock_at(month_end: date) -> int | None:
+        idx = bisect_right(flock_dates, month_end) - 1
+        return flock_counts[idx] if idx >= 0 else None
+
     results = []
     for row in egg_rows:
         y, m = int(row.year), int(row.month)
-        last_day  = calendar.monthrange(y, m)[1]
+        month_end = date(y, m, calendar.monthrange(y, m)[1])
-        month_end = date(y, m, last_day)
+        flock = flock_at(month_end)
-
-        flock_row = db.scalars(
-            select(FlockHistory)
-            .where(FlockHistory.user_id == uid)
-            .where(FlockHistory.date <= month_end)
-            .order_by(FlockHistory.date.desc())
-            .limit(1)
-        ).first()
-        flock = flock_row.chicken_count if flock_row else None
 
         total_eggs  = int(row.total_eggs)
         days_logged = int(row.days_logged)
@@ -192,11 +197,11 @@ def monthly_stats(
 
         raw_feed_cost  = feed_map.get((y, m))
         raw_other_cost = other_map.get((y, m))
-        feed_cost  = round(Decimal(str(raw_feed_cost)),  2) if raw_feed_cost  else None
+        feed_cost  = round(raw_feed_cost,  2) if raw_feed_cost  else None
-        other_cost = round(Decimal(str(raw_other_cost)), 2) if raw_other_cost else None
+        other_cost = round(raw_other_cost, 2) if raw_other_cost else None
 
-        raw_total_cost = (raw_feed_cost or 0) + (raw_other_cost or 0)
+        total_cost = (raw_feed_cost or Decimal(0)) + (raw_other_cost or Decimal(0))
-        cpe = round(Decimal(str(raw_total_cost)) / Decimal(total_eggs), 4) if (raw_total_cost and total_eggs) else None
+        cpe = round(total_cost / total_eggs, 4) if (total_cost and total_eggs) else None
         cpd = round(cpe * 12, 4) if cpe else None
 
         results.append(MonthlySummary(

nginx/html/js/dashboard.js

@@ -80,11 +80,16 @@ async function loadDashboard() {
     const msg = document.getElementById('msg');
 
     try {
-        // Fetch stats and recent eggs in parallel
+        // Fetch stats and recent eggs in parallel; eggs limited to last 30 days for chart + recent list
+        const tz = (typeof Auth !== 'undefined' && Auth.getUser()?.timezone) || 'UTC';
+        const start30 = new Date();
+        start30.setDate(start30.getDate() - 30);
+        const start30str = start30.toLocaleDateString('en-CA', { timeZone: tz });
+
         const [stats, budget, eggs] = await Promise.all([
             API.get('/api/stats/dashboard'),
             API.get('/api/stats/budget'),
-            API.get('/api/eggs'),
+            API.get(`/api/eggs?start=${start30str}`),
         ]);
 
         // Populate stat cards