feat: align portal center panel with side cards + redesign login page

- Portal: wrap .panel-head in matching card (border, radius, shadow) with
  cyan->purple left accent bar; h2 28px -> 20px; description right-aligned
  with vertical divider; top edge now aligns with side-menu & links-panel
- Login: switch from absolute-positioned icons to el-input prefix slot;
  layout brand row (logo + title + uppercase subtitle); add form-title
  section with gradient bar; consistent cyan focus; gradient button;
  dashed top divider for back-link; card width 420 -> 460
- Add .gitignore (node_modules, dist, __pycache__, .env, etc.)

backend/routes/portal.py

@@ -0,0 +1,94 @@
+"""Public portal API — no auth required."""
+from flask import Blueprint, jsonify, request
+
+from models import Category, Option, Resource, SideLink, SiteSetting
+
+bp = Blueprint("portal", __name__, url_prefix="/api/portal")
+
+
+@bp.route("/bootstrap")
+def bootstrap():
+    """Everything the portal page needs in one request."""
+    settings = {s.key: s.value for s in SiteSetting.query.all()}
+    categories = (
+        Category.query.filter_by(is_active=True)
+        .order_by(Category.sort_order, Category.id)
+        .all()
+    )
+    links = (
+        SideLink.query.filter_by(is_active=True)
+        .order_by(SideLink.sort_order, SideLink.id)
+        .all()
+    )
+    return jsonify({
+        "settings": settings,
+        "categories": [c.to_dict() for c in categories],
+        "links": [l.to_dict() for l in links],
+    })
+
+
+@bp.route("/categories/<int:cid>/resources")
+def category_resources(cid):
+    """Resources for a category, faceted by selected option ids."""
+    category = Category.query.get_or_404(cid)
+    selected = []
+    raw = request.args.get("option_ids", "")
+    keyword = request.args.get("keyword", "").strip()
+    if raw.strip():
+        try:
+            selected = [int(x) for x in raw.split(",") if x.strip()]
+        except ValueError:
+            selected = []
+
+    query = Resource.query.filter_by(category_id=cid, is_active=True)
+    if keyword:
+        query = query.filter(
+            Resource.title.like(f"%{keyword}%") |
+            Resource.description.like(f"%{keyword}%") |
+            Resource.content.like(f"%{keyword}%")
+        )
+    resources = query.order_by(Resource.sort_order, Resource.id).all()
+
+    if selected:
+        chosen = Option.query.filter(Option.id.in_(selected)).all()
+        by_row = {}
+        for o in chosen:
+            by_row.setdefault(o.row_id, []).append(o.id)
+
+        def matches(res):
+            tagged_ids = {o.id for o in res.options}
+            tagged_row_ids = {o.row_id for o in res.options}
+            for row_id, opt_ids in by_row.items():
+                if row_id not in tagged_row_ids:
+                    continue  # untagged in this row -> applies to all
+                if not tagged_ids.intersection(opt_ids):
+                    return False
+            return True
+
+        resources = [r for r in resources if matches(r)]
+
+    return jsonify({
+        "category": category.to_dict(),
+        "resources": [r.to_dict() for r in resources],
+        "selected_option_ids": selected,
+    })
+
+
+@bp.route("/search")
+def global_search():
+    """Global search across all resources."""
+    keyword = request.args.get("keyword", "").strip()
+    if not keyword or len(keyword) < 2:
+        return jsonify({"results": [], "keyword": keyword})
+
+    results = Resource.query.filter_by(is_active=True).filter(
+        Resource.title.like(f"%{keyword}%") |
+        Resource.description.like(f"%{keyword}%") |
+        Resource.content.like(f"%{keyword}%")
+    ).order_by(Resource.category_id, Resource.sort_order).limit(50).all()
+
+    return jsonify({
+        "keyword": keyword,
+        "count": len(results),
+        "results": [r.to_dict() for r in results]
+    })