fix(build): add shared-schema to prepare script for CI builds

The shared-schema package was not being built before lint and test
steps in CI, causing "Cannot find module '@sp/shared-schema'" errors.

Changes:
- Add shared-schema:build script to package.json
- Update prepare script to build shared-schema first
- Add shared-schema to build-packages.js for completeness

package.json

@@ -22,7 +22,7 @@
     "assemble:android:prod": "cd android && ./gradlew assembleRelease && cd ..",
     "assemble:android:stage": "cd android && ./gradlew assembleDebug && cd ..",
     "prebuild": "npm run env && node ./tools/git-version.js && npm run build:packages",
-    "prepare": "husky && ts-patch install && npm run plugin-api:build",
+    "prepare": "husky && ts-patch install && npm run shared-schema:build && npm run plugin-api:build",
     "build": "npm run buildAllElectron:noTests:prod",
     "build:packages": "node ./packages/build-packages.js",
     "buildAllElectron:noTests:prod": "npm run lint && npm run buildFrontend:prod:es6 && npm run electron:build",
@@ -125,6 +125,7 @@
     "checkFile": "node tools/check-file.js",
     "clean:translations": "node ./tools/clean-translations.js",
     "plugin-api:build": "cd packages/plugin-api && npm run build",
+    "shared-schema:build": "cd packages/shared-schema && npm run build",
     "plugin-api:build:watch": "cd packages/plugin-api && npm run build:watch",
     "vite-plugin:build": "cd packages/vite-plugin && npm run build",
     "plugins:build": "npm run vite-plugin:build && cd packages/plugin-dev && npm run build:all",

packages/build-packages.js

@@ -38,7 +38,15 @@ async function getPlugins() {
 
   const plugins = [];
 
-  // Add plugin-api first as it's a dependency
+  // Add shared-schema first as it's needed for type resolution
+  plugins.push({
+    name: 'shared-schema',
+    path: 'packages/shared-schema',
+    buildCommand: 'npm run build',
+    skipCopy: true,
+  });
+
+  // Add plugin-api as it's a dependency for plugins
   plugins.push({
     name: 'plugin-api',
     path: 'packages/plugin-api',
@@ -46,7 +54,7 @@ async function getPlugins() {
     skipCopy: true,
   });
 
-  // Add vite-plugin second as it's a build dependency
+  // Add vite-plugin as it's a build dependency
   plugins.push({
     name: 'vite-plugin',
     path: 'packages/vite-plugin',