feat: features 025-032 - favoritos, contatos, trabalhe-conosco, area-cliente, navbar, hero-light-dark, performance-homepage

- feat(025): favoritos locais com FavoritesContext, HeartButton, PublicFavoritesPage
- feat(026): central de contatos admin (leads/contatos unificados)
- feat(027): configuração da página de contato via admin
- feat(028): trabalhe conosco - candidaturas com upload e admin
- feat(029): UX área do cliente - visitas, comparação, perfil
- feat(030): navbar UX - menu mobile, ThemeToggle, useFavorites
- feat(031): hero light/dark - imagens separadas por tema, upload, preview, seed
- feat(032): performance homepage - Promise.all parallel fetches, sessionStorage cache,
  preload hero image, loading=lazy nos cards, useInView hook, will-change carrossel,
  keyframes em index.css, AgentsCarousel e HomeScrollScene via props
- fix: light mode HomeScrollScene - gradiente, cores de texto, scroll hint

migrations: g1h2i3j4k5l6 (source em leads), h1i2j3k4l5m6 (contact_config),
            i1j2k3l4m5n6 (job_applications), j2k3l4m5n6o7 (hero theme images)

backend/migrations/versions/g1h2i3j4k5l6_add_source_to_contact_leads.py

@@ -0,0 +1,32 @@
+"""add source and source_detail to contact_leads
+
+Revision ID: g1h2i3j4k5l6
+Revises: f2a3b4c5d6e7
+Create Date: 2026-04-21 00:00:00.000000
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "g1h2i3j4k5l6"
+down_revision = "f2a3b4c5d6e7"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.add_column(
+        "contact_leads",
+        sa.Column("source", sa.String(100), nullable=True),
+    )
+    op.add_column(
+        "contact_leads",
+        sa.Column("source_detail", sa.String(255), nullable=True),
+    )
+
+
+def downgrade():
+    op.drop_column("contact_leads", "source_detail")
+    op.drop_column("contact_leads", "source")