build(updates): enable full git history and use semantic version for runtimeVersion

Enable fetch-depth: 0 in checkout steps to support commit counting.
Switch runtimeVersion from buildNumber to appJson.expo.version so that
builds with the same semantic version share OTA update channels,
while versionCode/buildNumber continue using commit count for app store monotonic versioning.

.gitea/workflows/build.yml

@@ -36,6 +36,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - name: Set up Node
         uses: actions/setup-node@v4
@@ -108,6 +110,8 @@ jobs:
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
 
       - name: Set up Java
         uses: actions/setup-java@v4