chore: update project state and prepare for image support development

- Add comprehensive image test document with various image types
- Update project structure with development artifacts
- Prepare foundation for image support enhancement phase
- Include test files for validating image editing workflows

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

Co-Authored-By: Claude <noreply@anthropic.com>

node_modules/sprintf-js/gruntfile.js

@@ -0,0 +1,36 @@
+module.exports = function(grunt) {
+    grunt.initConfig({
+        pkg: grunt.file.readJSON("package.json"),
+
+        uglify: {
+            options: {
+                banner: "/*! <%= pkg.name %> | <%= pkg.author %> | <%= pkg.license %> */\n",
+                sourceMap: true
+            },
+            build: {
+                files: [
+                    {
+                        src: "src/sprintf.js",
+                        dest: "dist/sprintf.min.js"
+                    },
+                    {
+                        src: "src/angular-sprintf.js",
+                        dest: "dist/angular-sprintf.min.js"
+                    }
+                ]
+            }
+        },
+
+        watch: {
+            js: {
+                files: "src/*.js",
+                tasks: ["uglify"]
+            }
+        }
+    })
+
+    grunt.loadNpmTasks("grunt-contrib-uglify")
+    grunt.loadNpmTasks("grunt-contrib-watch")
+
+    grunt.registerTask("default", ["uglify", "watch"])
+}