refactor: migrate to modular tool-based architecture

- Implement tool registry system with individual tool modules
- Reorganize transformers into categorized source modules
- Remove emojiLibrary.js, consolidate into EmojiUtils and emojiData
- Fix mobile close button and tooltip functionality
- Add build system for transforms and emoji data
- Migrate from Python backend to pure JavaScript
- Add comprehensive documentation and testing
- Improve code organization and maintainability
- Ignore generated files (transforms-bundle.js, emojiData.js)

src/transformers/encoding/base45.js

@@ -0,0 +1,45 @@
+// base45 transform
+import BaseTransformer from '../BaseTransformer.js';
+
+export default new BaseTransformer({
+
+        name: 'Base45',
+    priority: 290,
+    alphabet: '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:',
+        func: function(text) {
+            const bytes = new TextEncoder().encode(text);
+            const chars = [];
+            for (let i=0;i<bytes.length;i+=2) {
+                if (i+1 < bytes.length) {
+                    const x = 256*bytes[i] + bytes[i+1];
+                    const e = x % 45; const d = Math.floor(x/45) % 45; const c = Math.floor(x/45/45);
+                    chars.push(this.alphabet[e], this.alphabet[d], this.alphabet[c]);
+                } else {
+                    const x = bytes[i];
+                    const e = x % 45; const d = Math.floor(x/45);
+                    chars.push(this.alphabet[e], this.alphabet[d]);
+                }
+            }
+            return chars.join('');
+        },
+        preview: function(text) {
+            if (!text) return 'QED8W';
+            return this.func(text.slice(0,3));
+        },
+        reverse: function(text) {
+            const index = {}; for (let i=0;i<this.alphabet.length;i++) index[this.alphabet[i]] = i;
+            const codes = [...text].map(c => index[c]).filter(v => v !== undefined);
+            const out = [];
+            for (let i=0;i<codes.length;i+=3) {
+                if (i+2 < codes.length) {
+                    const x = codes[i] + codes[i+1]*45 + codes[i+2]*45*45;
+                    out.push(x >> 8, x & 0xFF);
+                } else if (i+1 < codes.length) {
+                    const x = codes[i] + codes[i+1]*45;
+                    out.push(x & 0xFF);
+                }
+            }
+            return new TextDecoder().decode(Uint8Array.from(out));
+        }
+
+});