feat: Implement a core plugin system, integrate flag icon assets, and establish a GitHub release workflow.

src/js/editor.js

@@ -0,0 +1,74 @@
+import { basicSetup } from "codemirror"
+import { EditorView, keymap } from "@codemirror/view"
+import { html } from "@codemirror/lang-html"
+import { oneDark } from "@codemirror/theme-one-dark"
+import { EditorState } from "@codemirror/state"
+import { color } from "@uiw/codemirror-extensions-color"
+import { abbreviationTracker, expandAbbreviation } from "@emmetio/codemirror6-plugin"
+import { linter, lintGutter } from "@codemirror/lint"
+import { syntaxTree } from "@codemirror/language"
+
+// Simple linter that flags parser error nodes
+const htmlLinter = linter(view => {
+    const diagnostics = []
+    syntaxTree(view.state).iterate({
+        enter: (node) => {
+            if (node.type.isError) {
+                diagnostics.push({
+                    from: node.from,
+                    to: node.to,
+                    severity: "error",
+                    message: "Syntax error"
+                })
+            }
+        }
+    })
+    return diagnostics
+})
+
+// Expose to window for easy integration in PHP views
+window.MivoEditor = {
+    init: (options) => {
+        const { parent, initialValue, onChange, dark } = options;
+        
+        const extensions = [
+            basicSetup,
+            html(),
+            color,
+            htmlLinter,
+            lintGutter(),
+            abbreviationTracker({
+                syntax: 'html'
+            }),
+            keymap.of([
+                { key: 'Tab', run: expandAbbreviation },
+            ]),
+            EditorView.lineWrapping,
+            EditorView.updateListener.of((update) => {
+                if (update.docChanged && typeof onChange === 'function') {
+                    onChange(update.state.doc.toString());
+                }
+            })
+        ];
+
+        if (dark) {
+            extensions.push(oneDark);
+        }
+
+        const state = EditorState.create({
+            doc: initialValue || "",
+            extensions: extensions
+        });
+
+        const view = new EditorView({
+            state,
+            parent: parent
+        });
+
+        return view;
+    },
+    
+    // Helper to toggle theme without re-init if needed
+    // For simplicity now, we re-init or just use the initial state.
+    // In Mivo, most pages reload or can be handled via state updates.
+};