Translate the entire repo to English (UI strings, README, CI, comments)

Prep for public distribution. All user-facing strings, the README, the Gitea
workflow step names/comments and the keystore example are now English.
Follow-up i18n (string resources + locale files) is tracked in #5.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -1,6 +1,6 @@
 name: Build APK
 
-# Bouwt een getekende release-APK op elke versietag (v0.1.0, …) en op handmatige trigger.
+# Builds a signed release APK on every version tag (v0.1.0, …) and on manual trigger.
 on:
   push:
     tags:
@@ -9,26 +9,26 @@ on:
 
 jobs:
   build:
-    # Dedicated x86_64 runner (LXC op Proxmox) — de globale ARM64-runners hebben deze
-    # label niet, dus zij pikken deze job niet op.
+    # Dedicated x86_64 runner (LXC on Proxmox) — the global ARM64 runners don't have
+    # this label, so they won't pick up this job.
     runs-on: paperscan
-    # Laat het automatische Actions-token een release aanmaken + assets uploaden.
+    # Let the automatic Actions token create a release + upload assets.
     permissions:
       contents: write
-    # Image met Android SDK + JDK 17 + Gradle voorgeïnstalleerd.
+    # Image with Android SDK + JDK 17 + Gradle preinstalled.
     container:
       image: mingc/android-build-box:latest
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Herstel signing keystore uit secret
+      - name: Restore signing keystore from secret
         run: |
           echo "$SIGNING_KEYSTORE_BASE64" | base64 -d > "$GITHUB_WORKSPACE/release.jks"
         env:
           SIGNING_KEYSTORE_BASE64: ${{ secrets.SIGNING_KEYSTORE_BASE64 }}
 
-      - name: Genereer Gradle wrapper indien nodig
+      - name: Generate Gradle wrapper if needed
         run: |
           if [ ! -f gradle/wrapper/gradle-wrapper.jar ]; then
             gradle wrapper --gradle-version 8.11.1
@@ -44,7 +44,7 @@ jobs:
           SIGNING_KEY_ALIAS: ${{ secrets.SIGNING_KEY_ALIAS }}
           SIGNING_KEY_PASSWORD: ${{ secrets.SIGNING_KEY_PASSWORD }}
 
-      - name: Publiceer release met APK als download
+      - name: Publish release with APK as a download
         env:
           TOKEN: ${{ github.token }}
           TAG: ${{ github.ref_name }}
@@ -54,22 +54,22 @@ jobs:
           APK=$(ls app/build/outputs/apk/release/*.apk | head -1)
           AUTH="Authorization: token $TOKEN"
 
-          # Hergebruik een bestaande release voor deze tag, of maak 'm aan.
+          # Reuse an existing release for this tag, or create it.
           REL_ID=$(curl -sS -H "$AUTH" "$API/releases/tags/$TAG" | grep -oP '"id":\s*\K[0-9]+' | head -1 || true)
           if [ -z "$REL_ID" ]; then
             REL_ID=$(curl -sS -X POST "$API/releases" -H "$AUTH" -H "Content-Type: application/json" \
-              -d "{\"tag_name\":\"$TAG\",\"name\":\"PaperScan $TAG\",\"body\":\"Automatische build van $TAG.\"}" \
+              -d "{\"tag_name\":\"$TAG\",\"name\":\"PaperScan $TAG\",\"body\":\"Automated build of $TAG.\"}" \
               | grep -oP '"id":\s*\K[0-9]+' | head -1)
           fi
           echo "Release id: $REL_ID"
 
-          # Verwijder een eventueel bestaande asset met dezelfde naam (bij re-run/hertag).
+          # Remove any existing asset with the same name (on re-run/re-tag).
           ASSET_NAME="paperscan-$TAG.apk"
           OLD=$(curl -sS -H "$AUTH" "$API/releases/$REL_ID/assets" \
             | grep -oP "\"id\":\s*\K[0-9]+(?=[^}]*\"name\":\s*\"$ASSET_NAME\")" | head -1 || true)
           if [ -n "$OLD" ]; then curl -sS -X DELETE -H "$AUTH" "$API/releases/$REL_ID/assets/$OLD"; fi
 
-          # Upload de getekende APK als download-asset.
+          # Upload the signed APK as a downloadable asset.
           curl -sS -X POST "$API/releases/$REL_ID/assets?name=$ASSET_NAME" \
             -H "$AUTH" -H "Content-Type: application/octet-stream" \
             --data-binary @"$APK" | grep -oP '"browser_download_url":\s*"\K[^"]+' || true