fix: update keywords for better SEO

- Modify keywords in cities_controller.rb to include 'ai weather'
- Update keywords in weather_arts_controller.rb to include 'ai weather'
- Change keywords in application.html.erb to include 'ai weather'

These changes enhance the search engine optimization (SEO) of the
application by ensuring that relevant keywords are included in
meta tags, improving visibility for users searching for AI
weather-related content.

app/controllers/cities_controller.rb

@@ -46,7 +46,7 @@ class CitiesController < ApplicationController
     set_meta_tags(
       title: @city.name,
       description: "Experience #{@city.name}'s weather through AI-generated art. Daily updates of weather conditions visualized through artificial intelligence.",
-      keywords: "#{@city.name}, #{@city.country.name}, ai art, weather art, AI visualization",
+      keywords: "#{@city.name}, #{@city.country.name}, ai art, ai weather, weather art, AI visualization",
       og: {
         image: @city.latest_weather_art&.image&.attached? ? url_for(@city.latest_weather_art.image) : nil
       }

app/controllers/weather_arts_controller.rb

@@ -17,7 +17,7 @@ class WeatherArtsController < ApplicationController
     set_meta_tags(
       title: "#{@city.name} Weather Art - #{@weather_art.weather_date.strftime('%B %d, %Y')}",
       description: "#{@city.name}'s weather visualized through AI art. #{@weather_art.description} at #{@weather_art.temperature}°C.",
-      keywords: "#{@city.name}, #{@city.country.name}, ai art, weather art, AI visualization, #{@weather_art.description}",
+      keywords: "#{@city.name}, #{@city.country.name}, ai art, ai weather, weather art, AI visualization, #{@weather_art.description}",
       og: {
         image: @weather_art.image.attached? ? url_for(@weather_art.image) : nil
       }

app/views/layouts/application.html.erb

@@ -11,7 +11,7 @@
           og: {
             site_name: 'TodayAIWeather',
             type: 'website',
-            keywords: "ai art, weather art, AI visualization, today ai weather",
+            keywords: "ai art, ai weather, weather art, AI visualization, today ai weather",
             url: request.original_url
           },
           alternate: {