UI/UX Improvements: Modern design + hashtag system + cover images

- Added modern CSS design system with better typography
- Created hashtag/tag functionality with auto-tagging
- Improved homepage with hero section and trending tags
- Enhanced article pages with full-width cover images
- Added tag pages for filtering articles by hashtag
- Better mobile responsive design
- Smoother animations and transitions
- Auto-tag system analyzes content and assigns relevant tags
- 30+ predefined AI-related tags (ChatGPT, OpenAI, etc.)

database/tags_migration.sql

@@ -0,0 +1,79 @@
+-- Add tags/hashtags system to Burmddit
+-- Run this migration to add tag functionality
+
+-- Tags are already in schema.sql, but let's ensure everything is ready
+
+-- Add some default popular tags if they don't exist
+INSERT INTO tags (name, name_burmese, slug) VALUES
+('Breaking News', 'လတ်တလော သတင်း', 'breaking-news'),
+('Tutorial', 'သင်ခန်းစာ', 'tutorial'),
+('OpenAI', 'OpenAI', 'openai'),
+('Google', 'Google', 'google'),
+('Microsoft', 'Microsoft', 'microsoft'),
+('Meta', 'Meta', 'meta'),
+('DeepMind', 'DeepMind', 'deepmind'),
+('Language Models', 'ဘာသာစကား မော်ဒယ်များ', 'language-models'),
+('Computer Vision', 'Computer Vision', 'computer-vision'),
+('Robotics', 'စက်ရုပ်နည်းပညာ', 'robotics'),
+('Ethics', 'ကျင့်ဝတ်', 'ethics'),
+('Research', 'သုတေသန', 'research'),
+('Startup', 'စတင်လုပ်ငန်း', 'startup'),
+('Funding', 'ရန်ပုံငွေ', 'funding'),
+('Product Launch', 'ထုတ်ကုန်အသစ်', 'product-launch')
+ON CONFLICT (slug) DO NOTHING;
+
+-- Function to auto-generate tags from article content
+CREATE OR REPLACE FUNCTION extract_tags_from_content(content_text TEXT)
+RETURNS TEXT[] AS $$
+DECLARE
+    tag_keywords TEXT[] := ARRAY[
+        'ChatGPT', 'GPT-4', 'GPT-5', 'OpenAI', 'Claude', 'Anthropic',
+        'Google', 'Gemini', 'Microsoft', 'Copilot', 'Meta', 'Llama',
+        'DeepMind', 'DeepSeek', 'Mistral', 'Hugging Face',
+        'AGI', 'LLM', 'AI Safety', 'Neural Network', 'Transformer',
+        'Machine Learning', 'Deep Learning', 'NLP', 'Computer Vision',
+        'Robotics', 'Autonomous', 'Generative AI'
+    ];
+    found_tags TEXT[] := ARRAY[]::TEXT[];
+    keyword TEXT;
+BEGIN
+    FOREACH keyword IN ARRAY tag_keywords
+    LOOP
+        IF content_text ILIKE '%' || keyword || '%' THEN
+            found_tags := array_append(found_tags, keyword);
+        END IF;
+    END LOOP;
+    
+    RETURN found_tags;
+END;
+$$ LANGUAGE plpgsql;
+
+-- View for articles with tags
+CREATE OR REPLACE VIEW articles_with_tags AS
+SELECT 
+    a.id,
+    a.slug,
+    a.title_burmese,
+    a.excerpt_burmese,
+    a.featured_image,
+    a.category_id,
+    c.name_burmese as category_name_burmese,
+    c.slug as category_slug,
+    a.published_at,
+    a.view_count,
+    a.reading_time,
+    COALESCE(
+        array_agg(t.name_burmese) FILTER (WHERE t.id IS NOT NULL),
+        ARRAY[]::VARCHAR[]
+    ) as tags_burmese,
+    COALESCE(
+        array_agg(t.slug) FILTER (WHERE t.id IS NOT NULL),
+        ARRAY[]::VARCHAR[]
+    ) as tag_slugs
+FROM articles a
+LEFT JOIN categories c ON a.category_id = c.id
+LEFT JOIN article_tags at ON a.id = at.article_id
+LEFT JOIN tags t ON at.tag_id = t.id
+WHERE a.status = 'published'
+GROUP BY a.id, c.id
+ORDER BY a.published_at DESC;