feat(public_page): allow unauthenticated browsing with auth-gated interactivity

- Add get_optional_user dependency; dashboard returns guest-safe payload
- AuthGuard only redirects /following and /notifications for guests
- Sidebar hides auth-required nav items and shows Sign In/Register for guests
- Dashboard shows trending bills as "Most Popular" for unauthenticated visitors
- FollowButton opens AuthModal instead of acting when not signed in
- Members page pins followed members at the top for quick unfollowing
- useFollows skips API call and invalidates dashboard on follow/unfollow

Authored-By: Jack Levy

backend/app/api/dashboard.py

@@ -6,7 +6,7 @@ from sqlalchemy import desc, select
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy.orm import selectinload
 
-from app.core.dependencies import get_current_user
+from app.core.dependencies import get_optional_user
 from app.database import get_db
 from app.models import Bill, BillBrief, Follow, TrendScore
 from app.models.user import User
@@ -15,11 +15,38 @@ from app.schemas.schemas import BillSchema
 router = APIRouter()
 
 
+async def _get_trending(db: AsyncSession) -> list[dict]:
+    trending_result = await db.execute(
+        select(Bill)
+        .options(selectinload(Bill.sponsor), selectinload(Bill.briefs), selectinload(Bill.trend_scores))
+        .join(TrendScore, Bill.bill_id == TrendScore.bill_id)
+        .where(TrendScore.score_date >= date.today() - timedelta(days=1))
+        .order_by(desc(TrendScore.composite_score))
+        .limit(10)
+    )
+    trending_bills = trending_result.scalars().unique().all()
+    return [_serialize_bill(b) for b in trending_bills]
+
+
+def _serialize_bill(bill: Bill) -> dict:
+    b = BillSchema.model_validate(bill)
+    if bill.briefs:
+        b.latest_brief = bill.briefs[0]
+    if bill.trend_scores:
+        b.latest_trend = bill.trend_scores[0]
+    return b.model_dump()
+
+
 @router.get("")
 async def get_dashboard(
     db: AsyncSession = Depends(get_db),
-    current_user: User = Depends(get_current_user),
+    current_user: User | None = Depends(get_optional_user),
 ):
+    trending = await _get_trending(db)
+
+    if current_user is None:
+        return {"feed": [], "trending": trending, "follows": {"bills": 0, "members": 0, "topics": 0}}
+
     # Load follows for the current user
     follows_result = await db.execute(
         select(Follow).where(Follow.user_id == current_user.id)
@@ -79,28 +106,9 @@ async def get_dashboard(
     # Sort feed by latest action date
     feed_bills.sort(key=lambda b: b.latest_action_date or date.min, reverse=True)
 
-    # 4. Trending bills (top 10 by composite score today)
-    trending_result = await db.execute(
-        select(Bill)
-        .options(selectinload(Bill.sponsor), selectinload(Bill.briefs), selectinload(Bill.trend_scores))
-        .join(TrendScore, Bill.bill_id == TrendScore.bill_id)
-        .where(TrendScore.score_date >= date.today() - timedelta(days=1))
-        .order_by(desc(TrendScore.composite_score))
-        .limit(10)
-    )
-    trending_bills = trending_result.scalars().unique().all()
-
-    def serialize_bill(bill: Bill) -> dict:
-        b = BillSchema.model_validate(bill)
-        if bill.briefs:
-            b.latest_brief = bill.briefs[0]
-        if bill.trend_scores:
-            b.latest_trend = bill.trend_scores[0]
-        return b.model_dump()
-
     return {
-        "feed": [serialize_bill(b) for b in feed_bills[:50]],
-        "trending": [serialize_bill(b) for b in trending_bills],
+        "feed": [_serialize_bill(b) for b in feed_bills[:50]],
+        "trending": trending,
         "follows": {
             "bills": len(followed_bill_ids),
             "members": len(followed_member_ids),

backend/app/core/dependencies.py

@@ -8,6 +8,7 @@ from app.database import get_db
 from app.models.user import User
 
 oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/login")
+oauth2_scheme_optional = OAuth2PasswordBearer(tokenUrl="/api/auth/login", auto_error=False)
 
 
 async def get_current_user(
@@ -30,6 +31,19 @@ async def get_current_user(
     return user
 
 
+async def get_optional_user(
+    token: str | None = Depends(oauth2_scheme_optional),
+    db: AsyncSession = Depends(get_db),
+) -> User | None:
+    if not token:
+        return None
+    try:
+        user_id = decode_token(token)
+        return await db.get(User, user_id)
+    except Exception:
+        return None
+
+
 async def get_current_admin(
     current_user: User = Depends(get_current_user),
 ) -> User: