feat(frontend): add API client, layout, and routing

- Create Axios-based API client with sources, jobs, and dashboard endpoints
- Add responsive Layout component with navigation sidebar
- Set up React Router with Dashboard, Backups, and Settings routes
- Configure TanStack Query provider with default options
- Use lucide-react for navigation icons

frontend/node_modules/tailwindcss/lib/util/negateValue.js

@@ -0,0 +1,36 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+Object.defineProperty(exports, "default", {
+    enumerable: true,
+    get: function() {
+        return negateValue;
+    }
+});
+function negateValue(value) {
+    value = `${value}`;
+    if (value === "0") {
+        return "0";
+    }
+    // Flip sign of numbers
+    if (/^[+-]?(\d+|\d*\.\d+)(e[+-]?\d+)?(%|\w+)?$/.test(value)) {
+        return value.replace(/^[+-]?/, (sign)=>sign === "-" ? "" : "-");
+    }
+    // What functions we support negating numeric values for
+    // var() isn't inherently a numeric function but we support it anyway
+    // The trigonometric functions are omitted because you'll need to use calc(…) with them _anyway_
+    // to produce generally useful results and that will be covered already
+    let numericFunctions = [
+        "var",
+        "calc",
+        "min",
+        "max",
+        "clamp"
+    ];
+    for (const fn of numericFunctions){
+        if (value.includes(`${fn}(`)) {
+            return `calc(${value} * -1)`;
+        }
+    }
+}