Initial commit: homelab dashboard

Elixir + Phoenix dashboard displaying public and internal homelab
services. Internal services are shown only when the request originates
from the local network, detected server-side via conn.remote_ip with
Traefik trusted as a proxy (RemoteIp plug).

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

lib/homelab_dashboard_web/controllers/page_controller.ex

@@ -0,0 +1,95 @@
+defmodule HomelabDashboardWeb.PageController do
+  use HomelabDashboardWeb, :controller
+  import Bitwise
+
+  @public_services [
+    %{
+      name: "MTG",
+      url: "https://adyrem.duckdns.org/mtg",
+      description: "Magic: The Gathering collection",
+      icon: "hero-puzzle-piece"
+    },
+    %{
+      name: "Gitea",
+      url: "https://adyrem.duckdns.org/git",
+      description: "Git repository hosting",
+      icon: "hero-code-bracket"
+    }
+  ]
+
+  @internal_services [
+    %{
+      name: "Proxmox",
+      url: "https://proxmox.homelab",
+      description: "Virtualization & container management",
+      icon: "hero-server"
+    },
+    %{
+      name: "Grafana",
+      url: "https://grafana.homelab",
+      description: "Metrics & monitoring dashboards",
+      icon: "hero-chart-bar"
+    },
+    %{
+      name: "Pi-hole",
+      url: "https://pihole.homelab/admin",
+      description: "Network-wide DNS ad blocker",
+      icon: "hero-shield-check"
+    },
+    %{
+      name: "Jellyfin",
+      url: "https://jellyfin.homelab",
+      description: "Media server",
+      icon: "hero-film"
+    },
+    %{
+      name: "Jellyseerr",
+      url: "https://jellyseerr.homelab",
+      description: "Media request management",
+      icon: "hero-ticket"
+    },
+    %{
+      name: "Radarr",
+      url: "https://radarr.homelab",
+      description: "Movie collection manager",
+      icon: "hero-video-camera"
+    },
+    %{
+      name: "Sonarr",
+      url: "https://sonarr.homelab",
+      description: "TV series collection manager",
+      icon: "hero-tv"
+    },
+    %{
+      name: "Prowlarr",
+      url: "https://prowlarr.homelab",
+      description: "Indexer manager",
+      icon: "hero-magnifying-glass"
+    },
+    %{
+      name: "qBittorrent",
+      url: "https://qbittorrent.homelab",
+      description: "Torrent client",
+      icon: "hero-arrow-down-tray"
+    }
+  ]
+
+  def home(conn, _params) do
+    render(conn, :home,
+      public_services: @public_services,
+      internal_services: @internal_services,
+      show_internal: internal_network?(conn.remote_ip)
+    )
+  end
+
+  defp internal_network?({127, _, _, _}), do: true
+  defp internal_network?({10, _, _, _}), do: true
+  defp internal_network?({192, 168, _, _}), do: true
+  defp internal_network?({172, b, _, _}) when b in 16..31, do: true
+  defp internal_network?({0, 0, 0, 0, 0, 0, 0, 1}), do: true
+  # IPv6-mapped IPv4: ::ffff:x.x.x.x — decode and re-check
+  defp internal_network?({0, 0, 0, 0, 0, 65535, ab, cd}) do
+    internal_network?({ab >>> 8, ab &&& 0xFF, cd >>> 8, cd &&& 0xFF})
+  end
+  defp internal_network?(_), do: false
+end