Initial commit: notification-elements-demo app

Interactive Angular 19 demo for @sda/notification-elements-ui with
6 sections: Bell & Feed, Notification Center, Inbox, Comments &
Threads, Mention Input, and Full-Featured layout. Includes mock
data, dark mode toggle, and real-time event log.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

node_modules/lines-and-columns/build/index.d.ts

@@ -0,0 +1,13 @@
+export declare type SourceLocation = {
+    line: number;
+    column: number;
+};
+export declare class LinesAndColumns {
+    private string;
+    private offsets;
+    constructor(string: string);
+    locationForIndex(index: number): SourceLocation | null;
+    indexForLocation(location: SourceLocation): number | null;
+    private lengthOfLine;
+}
+export default LinesAndColumns;

node_modules/lines-and-columns/build/index.js

@@ -0,0 +1,62 @@
+"use strict";
+exports.__esModule = true;
+exports.LinesAndColumns = void 0;
+var LF = '\n';
+var CR = '\r';
+var LinesAndColumns = /** @class */ (function () {
+    function LinesAndColumns(string) {
+        this.string = string;
+        var offsets = [0];
+        for (var offset = 0; offset < string.length;) {
+            switch (string[offset]) {
+                case LF:
+                    offset += LF.length;
+                    offsets.push(offset);
+                    break;
+                case CR:
+                    offset += CR.length;
+                    if (string[offset] === LF) {
+                        offset += LF.length;
+                    }
+                    offsets.push(offset);
+                    break;
+                default:
+                    offset++;
+                    break;
+            }
+        }
+        this.offsets = offsets;
+    }
+    LinesAndColumns.prototype.locationForIndex = function (index) {
+        if (index < 0 || index > this.string.length) {
+            return null;
+        }
+        var line = 0;
+        var offsets = this.offsets;
+        while (offsets[line + 1] <= index) {
+            line++;
+        }
+        var column = index - offsets[line];
+        return { line: line, column: column };
+    };
+    LinesAndColumns.prototype.indexForLocation = function (location) {
+        var line = location.line, column = location.column;
+        if (line < 0 || line >= this.offsets.length) {
+            return null;
+        }
+        if (column < 0 || column > this.lengthOfLine(line)) {
+            return null;
+        }
+        return this.offsets[line] + column;
+    };
+    LinesAndColumns.prototype.lengthOfLine = function (line) {
+        var offset = this.offsets[line];
+        var nextOffset = line === this.offsets.length - 1
+            ? this.string.length
+            : this.offsets[line + 1];
+        return nextOffset - offset;
+    };
+    return LinesAndColumns;
+}());
+exports.LinesAndColumns = LinesAndColumns;
+exports["default"] = LinesAndColumns;