Disable critical-CSS inlining so the stylesheet survives the CSP

Angular's production build defers the main stylesheet with
`media="print" onload="this.media='all'"` and inlines a critical subset
ahead of it. The nginx CSP sets `script-src 'self'`, which blocks that
inline event handler — so the swap never ran and the stylesheet stayed
print-only. The app rendered from the ~23kB critical subset alone.

Most of the page still looked right, which is what made it easy to miss.
Material icons did not: `.material-icons` was not in the critical subset,
so every icon fell back to the body font and rendered its ligature name
("videogame_asset") clipped to the icon box.

`inlineCritical: false` emits a plain <link rel="stylesheet">. The
stylesheet is 24kB and same-origin, so the optimisation bought little and
cost correctness under a strict CSP.

Verified in headless Chromium: icons render as glyphs across the toolbar,
grid, editor and mobile layouts, and the console is now clean where it
previously logged four CSP violations per page load.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

frontend/angular.json

@@ -51,7 +51,15 @@
                   "maximumError": "8kB"
                 }
               ],
-              "outputHashing": "all"
+              "outputHashing": "all",
+              "optimization": {
+                "scripts": true,
+                "styles": {
+                  "minify": true,
+                  "inlineCritical": false
+                },
+                "fonts": true
+              }
             },
             "development": {
               "optimization": false,