fix: remove colon from word selection characters

Author: sreya

lib/selection-manager.ts

@@ -911,11 +911,11 @@ export class SelectionManager {
 
     // Word characters: letters, numbers, and common path/URL characters
     // Matches native Ghostty behavior where double-click selects entire paths
-    // Includes: / (path sep), . (extensions), ~ (home), : (line numbers), @ (emails)
+    // Includes: / (path sep), . (extensions), ~ (home), @ (emails), + (encodings)
     const isWordChar = (cell: GhosttyCell) => {
       if (!cell || cell.codepoint === 0) return false;
       const char = String.fromCodePoint(cell.codepoint);
-      return /[\w\-./~:@+]/.test(char);
+      return /[\w\-./~@+]/.test(char);
     };
 
     // Only return if we're actually on a word character