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

crates/guara-core/tests/common/mod.rs

@@ -37,7 +37,7 @@ impl Sink for Collect {
     }
 }
 
-/// Isola as configurações/sessões automáticas dos testes numa pasta temporária.
+/// Isolates `GUARA_CONFIG_DIR` (settings and autosaved sessions) inside a per-test temp directory.
 pub fn init() {
     static DIR: std::sync::OnceLock<tempfile::TempDir> = std::sync::OnceLock::new();
     let d = DIR.get_or_init(|| tempfile::tempdir().unwrap());
@@ -69,7 +69,7 @@ pub fn sha256(b: &[u8]) -> String {
         .collect()
 }
 
-/// Gera (uma vez) as imagens de teste; `None` se as ferramentas não existirem.
+/// Builds (or reuses) the filesystem test fixtures once per test binary; returns `None` if `mkfs` tools are missing.
 pub fn fixtures() -> Option<PathBuf> {
     static ONCE: std::sync::OnceLock<Option<PathBuf>> = std::sync::OnceLock::new();
     ONCE.get_or_init(fixtures_inner).clone()