feat: add JJOptimist's Homepage realm to examples (#3405)

This pull request adds a new realm example to the Gno examples
repository—JJOptimist's Homepage.

The realm includes:
- Personal introduction and contact information
- Configuration management system
- Owner controls 
- Tests for ownership and rendering

---------

Co-authored-by: Leon Hudak <33522493+leohhhn@users.noreply.github.com>

examples/gno.land/r/jjoptimist/home/config.gno

@@ -0,0 +1,32 @@
+package home
+
+import (
+	"std"
+
+	"gno.land/p/demo/ownable"
+)
+
+type Config struct {
+	Title       string
+	Description string
+	Github      string
+}
+
+var config = Config{
+	Title:       "JJOptimist's Home Realm 🏠",
+	Description: "Exploring Gno and building on-chain",
+	Github:      "jjoptimist",
+}
+
+var Ownable = ownable.NewWithAddress(std.Address("g16vfw3r7zuz43fhky3xfsuc2hdv9tnhvlkyn0nj"))
+
+func GetConfig() Config {
+	return config
+}
+
+func UpdateConfig(newTitle, newDescription, newGithub string) {
+	Ownable.AssertCallerIsOwner()
+	config.Title = newTitle
+	config.Description = newDescription
+	config.Github = newGithub
+}

examples/gno.land/r/jjoptimist/home/gno.mod

@@ -0,0 +1 @@
+module gno.land/r/jjoptimist/home

examples/gno.land/r/jjoptimist/home/home.gno

@@ -0,0 +1,82 @@
+package home
+
+import (
+	"std"
+	"strconv"
+	"time"
+
+	"gno.land/r/leon/hof"
+)
+
+const (
+	gnomeArt1 = `   /\
+  /  \
+ ,,,,,
+(o.o)
+(\_/)
+-"-"-`
+
+	gnomeArt2 = `   /\
+  /  \
+ ,,,,,
+(^.^)
+(\_/)
+ -"-`
+
+	gnomeArt3 = `   /\
+  /  \
+ ,,,,,
+(*.*)
+(\_/)
+"-"-"`
+
+	gnomeArt4 = `   /\
+  /  \
+ ,,,,,
+(o.~)
+(\_/)
+ -"-`
+)
+
+var creation time.Time
+
+func getGnomeArt(height int64) string {
+	var art string
+	switch {
+	case height%7 == 0:
+		art = gnomeArt4 // winking gnome
+	case height%5 == 0:
+		art = gnomeArt3 // starry-eyed gnome
+	case height%3 == 0:
+		art = gnomeArt2 // happy gnome
+	default:
+		art = gnomeArt1 // regular gnome
+	}
+	return "```\n" + art + "\n```\n"
+}
+
+func init() {
+	creation = time.Now()
+	hof.Register()
+}
+
+func Render(path string) string {
+	height := std.GetHeight()
+
+	output := "# " + config.Title + "\n\n"
+
+	output += "## About Me\n"
+	output += "- 👋 Hi, I'm JJOptimist\n"
+	output += getGnomeArt(height)
+	output += "- 🌱 " + config.Description + "\n"
+
+	output += "## Contact\n"
+	output += "- 📫 GitHub: [" + config.Github + "](https://github.com/" + config.Github + ")\n"
+
+	output += "\n---\n"
+	output += "_Realm created: " + creation.Format("2006-01-02 15:04:05 UTC") + "_\n"
+	output += "_Owner: " + Ownable.Owner().String() + "_\n"
+	output += "_Current Block Height: " + strconv.Itoa(int(height)) + "_"
+
+	return output
+}

examples/gno.land/r/jjoptimist/home/home_test.gno

@@ -0,0 +1,60 @@
+package home
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestConfig(t *testing.T) {
+	cfg := GetConfig()
+
+	if cfg.Title != "JJOptimist's Home Realm 🏠" {
+		t.Errorf("Expected title to be 'JJOptimist's Home Realm 🏠', got %s", cfg.Title)
+	}
+	if cfg.Description != "Exploring Gno and building on-chain" {
+		t.Errorf("Expected description to be 'Exploring Gno and building on-chain', got %s", cfg.Description)
+	}
+	if cfg.Github != "jjoptimist" {
+		t.Errorf("Expected github to be 'jjoptimist', got %s", cfg.Github)
+	}
+}
+
+func TestRender(t *testing.T) {
+	output := Render("")
+
+	// Test that required sections are present
+	if !strings.Contains(output, "# "+config.Title) {
+		t.Error("Rendered output missing title")
+	}
+	if !strings.Contains(output, "## About Me") {
+		t.Error("Rendered output missing About Me section")
+	}
+	if !strings.Contains(output, "## Contact") {
+		t.Error("Rendered output missing Contact section")
+	}
+	if !strings.Contains(output, config.Description) {
+		t.Error("Rendered output missing description")
+	}
+	if !strings.Contains(output, config.Github) {
+		t.Error("Rendered output missing github link")
+	}
+}
+
+func TestGetGnomeArt(t *testing.T) {
+	tests := []struct {
+		height   int64
+		expected string
+	}{
+		{7, gnomeArt4}, // height divisible by 7
+		{5, gnomeArt3}, // height divisible by 5
+		{3, gnomeArt2}, // height divisible by 3
+		{2, gnomeArt1}, // default case
+	}
+
+	for _, tt := range tests {
+		art := getGnomeArt(tt.height)
+		if !strings.Contains(art, tt.expected) {
+			t.Errorf("For height %d, expected art containing %s, got %s", tt.height, tt.expected, art)
+		}
+	}
+}