chore(i18n): finish translating code comments and scripts to English

Completes the English-only standardization for code, comments, scripts
and CI templates (UI/CLI-facing strings stay bilingual pt-BR/en,
untouched). Covers the remaining crates/, apps/gui/ui/ and
apps/gui/src-tauri/ comments, .gitea/ workflow and template comments,
.githooks/ hooks, and the scripts/ source comments for the files
already renamed in a prior commit (check.sh, generate-logo.py,
install-hooks.sh).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VAyr8d7HuAdUGB6aA5xmDD

scripts/fetch-testdata.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
-# Baixa imagens de referência (BitLocker e FileVault2) do conjunto de testes do cryptsetup.
-# Ficam em target/testdata (não versionado). Sem elas, os testes correspondentes são pulados.
+# Downloads reference disk images (BitLocker, FileVault 2, dfvfs, AFF4) used by integration tests.
+# Stored in target/testdata (untracked). When absent, the corresponding tests are skipped.
 set -euo pipefail
 dest="$(cd "$(dirname "$0")/.." && pwd)/target/testdata"
 mkdir -p "$dest"