feat(workflows): 'Clean up layout' auto-arrange button (dagre)

Adds a one-click tidy that re-lays the graph top-to-bottom with dagre
(@dagrejs/dagre) and fits the view — handles the loop-back cycle by breaking
it internally. en + de string.

frontend/package-lock.json

@@ -8,6 +8,7 @@
       "name": "picpeak-frontend",
       "version": "3.69.0-beta.0",
       "dependencies": {
+        "@dagrejs/dagre": "^3.0.0",
         "@fullcalendar/core": "^6.1.20",
         "@fullcalendar/daygrid": "^6.1.20",
         "@fullcalendar/interaction": "^6.1.20",
@@ -549,6 +550,21 @@
         "node": ">=18"
       }
     },
+    "node_modules/@dagrejs/dagre": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/@dagrejs/dagre/-/dagre-3.0.0.tgz",
+      "integrity": "sha512-ZzhnTy1rfuoew9Ez3EIw4L2znPGnYYhfn8vc9c4oB8iw6QAsszbiU0vRhlxWPFnmmNSFAkrYeF1PhM5m4lAN0Q==",
+      "license": "MIT",
+      "dependencies": {
+        "@dagrejs/graphlib": "4.0.1"
+      }
+    },
+    "node_modules/@dagrejs/graphlib": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/@dagrejs/graphlib/-/graphlib-4.0.1.tgz",
+      "integrity": "sha512-IvcV6FduIIAmLwnH+yun+QtV36SC7mERqa86aClNqmMN09WhmPPYU8ckHrZBozErf+UvHPWOTJYaGYiIcs0DgA==",
+      "license": "MIT"
+    },
     "node_modules/@epic-web/invariant": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/@epic-web/invariant/-/invariant-1.0.0.tgz",