fix(core): restore theme.css compatibility export

.changeset/cool-forks-juggle.md

@@ -0,0 +1,7 @@
+---
+"@tailor-platform/app-shell": patch
+---
+
+Restore the `@tailor-platform/app-shell/theme.css` export as a no-op compatibility shim.
+
+Apps that still import `@tailor-platform/app-shell/theme.css` alongside `@tailor-platform/app-shell/styles` now keep building while the real theme tokens continue to come from `styles`.

packages/core/package.json

@@ -28,6 +28,7 @@
   "type": "module",
   "exports": {
     "./styles": "./dist/app-shell.css",
+    "./theme.css": "./dist/theme.shims.css",
     "./themes/*": "./dist/themes/*.css",
     ".": {
       "types": "./dist/app-shell.d.ts",

packages/core/src/assets/theme.shims.css

@@ -0,0 +1,7 @@
+/*
+ * Deprecated compatibility shim.
+ *
+ * `@tailor-platform/app-shell/styles` now includes the default theme tokens,
+ * so this file intentionally does nothing. Keep exporting it so older apps
+ * that still import `@tailor-platform/app-shell/theme.css` keep building.
+ */