Fix emoji loading inefficiency with intelligent resolver

- Add emoji-resolver.js that loads filename mappings from API
- Replace hardcoded .png/.gif extensions with placeholder images
- Eliminate 404 errors by using correct extensions from the start
- Support any file extension (.png, .gif, .jpg, .webp, etc.)
- Maintain backward compatibility for existing data

The resolver loads once, caches the mappings, and updates all emoji
images with their correct filenames, preventing unnecessary 404s.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[e-mail]>

static/emoji-resolver.js

···
+// Emoji Resolver Module - Handles mapping emoji names to correct filenames
+(function() {
+    'use strict';
+    
+    // Cache for emoji name -> filename mapping
+    let emojiMap = null;
+    let loadPromise = null;
+    
+    // Load emoji mapping from API
+    async function loadEmojiMap() {
+        if (emojiMap) return emojiMap;
+        if (loadPromise) return loadPromise;
+        
+        loadPromise = fetch('/api/custom-emojis')
+            .then(response => response.json())
+            .then(data => {
+                if (!Array.isArray(data)) {
+                    console.error('Invalid emoji data received');
+                    return new Map();
+                }
+                emojiMap = new Map(data.map(emoji => [emoji.name, emoji.filename]));
+                return emojiMap;
+            })
+            .catch(err => {
+                console.error('Failed to load emoji map:', err);
+                emojiMap = new Map();
+                return emojiMap;
+            });
+        
+        return loadPromise;
+    }
+    
+    // Get the correct emoji filename for a given name
+    function getEmojiFilename(emojiName) {
+        if (!emojiMap) return null;
+        return emojiMap.get(emojiName);
+    }
+    
+    // Update a single emoji image element
+    function updateEmojiImage(img) {
+        const emojiName = img.getAttribute('data-emoji-name');
+        if (!emojiName) return;
+        
+        const filename = getEmojiFilename(emojiName);
+        if (filename) {
+            // Found the correct filename, update src
+            img.src = `/emojis/${filename}`;
+            // Remove placeholder class if present
+            img.classList.remove('emoji-placeholder');
+            // Remove the error handler since we have the correct path
+            img.onerror = null;
+        } else {
+            // Emoji not found in map, try common extensions as fallback
+            // This handles newly added emojis that aren't in the cached map yet
+            img.src = `/emojis/${emojiName}.png`;
+            img.onerror = function() {
+                this.onerror = null;
+                this.src = `/emojis/${emojiName}.gif`;
+            };
+            img.classList.remove('emoji-placeholder');
+        }
+    }
+    
+    // Update all emoji images on the page
+    function updateAllEmojiImages() {
+        const images = document.querySelectorAll('img[data-emoji-name]');
+        images.forEach(updateEmojiImage);
+    }
+    
+    // Initialize on DOM ready
+    async function initialize() {
+        // Load the emoji map
+        await loadEmojiMap();
+        // Update all existing emoji images
+        updateAllEmojiImages();
+        
+        // Set up a MutationObserver to handle dynamically added content
+        const observer = new MutationObserver((mutations) => {
+            mutations.forEach((mutation) => {
+                mutation.addedNodes.forEach((node) => {
+                    if (node.nodeType === Node.ELEMENT_NODE) {
+                        // Check if the added node is an emoji image
+                        if (node.tagName === 'IMG' && node.getAttribute('data-emoji-name')) {
+                            updateEmojiImage(node);
+                        }
+                        // Also check descendants
+                        const images = node.querySelectorAll?.('img[data-emoji-name]');
+                        images?.forEach(updateEmojiImage);
+                    }
+                });
+            });
+        });
+        
+        // Start observing the document body for changes
+        observer.observe(document.body, {
+            childList: true,
+            subtree: true
+        });
+    }
+    
+    // Export to global scope
+    window.EmojiResolver = {
+        loadEmojiMap,
+        getEmojiFilename,
+        updateEmojiImage,
+        updateAllEmojiImages,
+        initialize
+    };
+    
+    // Auto-initialize when DOM is ready
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', initialize);
+    } else {
+        // DOM is already ready
+        initialize();
+    }
+})();

templates/base.html

···
     <!-- Markdown link renderer for statuses -->
     <script src="/static/markdown.js"></script>
     
+    <!-- Emoji Resolver for correct file extensions -->
+    <script src="/static/emoji-resolver.js"></script>
+    
     <!-- Apply User Settings -->
     <script>
         // Apply saved settings immediately to prevent flash

templates/feed.html

···
                     <span class="status-emoji">
                         {% if status.status.starts_with("custom:") %}
                             {% let emoji_name = status.status.strip_prefix("custom:").unwrap() %}
-                            <img src="/emojis/{{emoji_name}}.png" alt="{{emoji_name}}" title="{{emoji_name}}" class="custom-emoji-display"
-                                 onerror="this.onerror=null; this.src='/emojis/{{emoji_name}}.gif';">
+                            <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" 
+                                 alt="{{emoji_name}}" title="{{emoji_name}}" class="custom-emoji-display emoji-placeholder"
+                                 data-emoji-name="{{emoji_name}}">
                         {% else %}
                             <span title="{{status.status}}">{{status.status}}</span>
                         {% endif %}
···
             let emojiHtml = '';
             if (status.status.startsWith('custom:')) {
                 const emojiName = status.status.substring(7);
-                emojiHtml = `<img src="/emojis/${emojiName}.png" alt="${emojiName}" title="${emojiName}" class="custom-emoji-display" onerror="this.onerror=null; this.src='/emojis/${emojiName}.gif';">`;
+                emojiHtml = `<img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" alt="${emojiName}" title="${emojiName}" class="custom-emoji-display emoji-placeholder" data-emoji-name="${emojiName}">`;
             } else {
                 emojiHtml = `<span title="${status.status}">${status.status}</span>`;
             }

templates/status.html

···
                 <span class="status-emoji">
                     {% if current.status.starts_with("custom:") %}
                         {% let emoji_name = current.status.strip_prefix("custom:").unwrap() %}
-                        <img src="/emojis/{{emoji_name}}.png" alt="{{emoji_name}}" title="{{emoji_name}}" class="custom-emoji-display"
-                             onerror="this.onerror=null; this.src='/emojis/{{emoji_name}}.gif';">
+                        <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" 
+                             alt="{{emoji_name}}" title="{{emoji_name}}" class="custom-emoji-display emoji-placeholder"
+                             data-emoji-name="{{emoji_name}}">
                     {% else %}
                         <span title="{{ current.status }}">{{ current.status }}</span>
                     {% endif %}
···
                                 {% if let Some(current) = current_status.as_ref() %}
                                     {% if current.status.starts_with("custom:") %}
                                         {% let emoji_name = current.status.strip_prefix("custom:").unwrap() %}
-                                        <img src="/emojis/{{emoji_name}}.png" alt="{{emoji_name}}" title="{{emoji_name}}"
-                                             onerror="this.onerror=null; this.src='/emojis/{{emoji_name}}.gif';">
+                                        <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" 
+                                             alt="{{emoji_name}}" title="{{emoji_name}}" class="emoji-placeholder"
+                                             data-emoji-name="{{emoji_name}}">
                                     {% else %}
                                         <span title="{{ current.status }}">{{ current.status }}</span>
                                     {% endif %}
···
                 <span class="history-emoji">
                     {% if status.status.starts_with("custom:") %}
                         {% let emoji_name = status.status.strip_prefix("custom:").unwrap() %}
-                        <img src="/emojis/{{emoji_name}}.png" alt="{{emoji_name}}" title="{{emoji_name}}" class="custom-emoji-display"
-                             onerror="this.onerror=null; this.src='/emojis/{{emoji_name}}.gif';">
+                        <img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" 
+                             alt="{{emoji_name}}" title="{{emoji_name}}" class="custom-emoji-display emoji-placeholder"
+                             data-emoji-name="{{emoji_name}}">
                     {% else %}
                         <span title="{{ status.status }}">{{ status.status }}</span>
                     {% endif %}