fix(ci): correct workflow branch targets from main to master

All three GitHub Actions workflows (CI, E2E, Deploy) referenced
branches: [main] but the repository default branch is master.
This meant CI never triggered on pushes or PRs to master.

- ci.yml: push/PR triggers → master
- e2e.yml: push/PR triggers → master
- deploy.yml: push trigger + latest tag condition → master

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.github/workflows/e2e.yml

@@ -2,9 +2,9 @@ name: E2E Tests
 
 on:
   push:
-    branches: [main]
+    branches: [master]
   pull_request:
-    branches: [main]
+    branches: [master]
 
 concurrency:
   group: e2e-${{ github.ref }}