fix: pass github token to setup-protoc to avoid rate limits

arduino/setup-protoc downloads from GitHub releases which gets
rate-limited without authentication. Add a github-token input to the
setup action and pass GITHUB_TOKEN from the tauri workflow.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dakom

.github/actions/setup/action.yml

@@ -1,6 +1,12 @@
 name: "Repo setup"
 description: "Common CI setup steps (tools, deps, caches, etc.)"
 
+inputs:
+  github-token:
+    description: "GitHub token for authenticated API requests (avoids rate limits)"
+    required: false
+    default: ""
+
 runs:
   using: "composite"
   steps:
@@ -17,6 +23,8 @@ runs:
 
     - name: Install protoc
       uses: arduino/setup-protoc@v3
+      with:
+        repo-token: ${{ inputs.github-token }}
 
     - name: Install Rust
       uses: dtolnay/rust-toolchain@master

.github/workflows/tauri.yml

@@ -26,6 +26,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/setup
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Install Node.js
         uses: actions/setup-node@v4