Add Dashboard nav link for authenticated users

- Add conditional "Dashboard" link in navbar that shows when a user is logged in
- Tests verify the link is hidden for unauthenticated users and visible when authenticated
- Investigation reports for Q1 (drafts/scheduled), Q2 (RSS), Q3 (email subs)

app/test/firehose_web/controllers/page_controller_test.exs

@@ -1,9 +1,32 @@
 defmodule FirehoseWeb.PageControllerTest do
   use FirehoseWeb.ConnCase
 
-  test "GET /", %{conn: conn} do
-    body = conn |> get(~p"/") |> html_response(200)
-    assert body =~ "Drinking from the firehose"
-    assert body =~ "Willem van den Ende"
+  describe "GET /" do
+    test "renders the homepage", %{conn: conn} do
+      body = conn |> get(~p"/") |> html_response(200)
+      assert body =~ "Drinking from the firehose"
+      assert body =~ "Willem van den Ende"
+    end
+
+    test "shows navigation links", %{conn: conn} do
+      body = conn |> get(~p"/") |> html_response(200)
+      assert body =~ ~s|/blog/engineering|
+      assert body =~ ~s|/blog/releases|
+      assert body =~ ~s|/contact|
+    end
+
+    test "does not show dashboard link when unauthenticated", %{conn: conn} do
+      body = conn |> get(~p"/") |> html_response(200)
+      refute body =~ ~s|/editor/dashboard|
+    end
+  end
+
+  describe "GET / when authenticated" do
+    setup :register_and_log_in_user
+
+    test "shows dashboard link in navigation", %{conn: conn} do
+      body = conn |> get(~p"/") |> html_response(200)
+      assert body =~ ~s|/editor/dashboard|
+    end
   end
 end