Replace ambiguous-width icons that shift sidebar/file rows right

⬆ (U+2B06), 🖼 (U+1F5BC) and ⚙ (U+2699) are East-Asian-Width
Neutral: unicode-width measures 1 column but emoji fonts draw 2, so
every row containing them shifted right by one column. Replaced with
真 Wide emoji (📷, 🔩, ⚡) or pure text glyphs (↑, ≡), plus a
regression test asserting every emoji icon measures 2 columns.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/file_ops.rs

@@ -30,19 +30,24 @@ impl FileEntry {
                     .unwrap_or("")
                     .to_lowercase();
                 match ext.as_str() {
+                    // OBS: alla emoji-ikoner MÅSTE vara East-Asian-Width Wide
+                    // (mäts som 2 kolumner av unicode-width). Tecken med
+                    // EAW=Neutral/Ambiguous (t.ex. 🖼 U+1F5BC, ⚙ U+2699)
+                    // mäts som 1 men ritas 2 breda av emoji-fonter →
+                    // raden förskjuts åt höger. Se icon_widths-testet.
                     "rs" => "🦀",
-                    "png" | "jpg" | "jpeg" | "gif" | "bmp" | "svg" | "webp" | "ico" => "🖼",
+                    "png" | "jpg" | "jpeg" | "gif" | "bmp" | "svg" | "webp" | "ico" => "📷",
                     "mp4" | "mkv" | "avi" | "mov" | "webm" => "🎬",
                     "mp3" | "flac" | "ogg" | "wav" | "aac" => "🎵",
                     "zip" | "tar" | "gz" | "bz2" | "xz" | "7z" | "rar" => "📦",
                     "pdf" => "📕",
                     "txt" | "md" | "log" => "📄",
-                    "json" | "yaml" | "yml" | "toml" | "xml" => "⚙",
+                    "json" | "yaml" | "yml" | "toml" | "xml" => "🔩",
                     "sh" | "bash" | "zsh" | "fish" => "🐚",
                     "py" => "🐍",
                     "js" | "ts" => "📜",
                     "c" | "cpp" | "h" | "hpp" => "🔧",
-                    "exe" | "bin" | "out" | "run" => "⚙",
+                    "exe" | "bin" | "out" | "run" => "⚡",
                     _ => "📎",
                 }
             }
@@ -294,3 +299,56 @@ pub fn get_root_dirs() -> Vec<PathBuf> {
         drives
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use unicode_width::UnicodeWidthStr;
+
+    fn entry(name: &str, ft: FileType) -> FileEntry {
+        FileEntry {
+            name: name.to_string(),
+            path: PathBuf::from(name),
+            file_type: ft,
+            size: 0,
+            is_hidden: false,
+        }
+    }
+
+    /// Alla emoji-ikoner måste vara East-Asian-Width Wide (mäts som
+    /// 2 kolumner av unicode-width). En ikon med EAW=Neutral/Ambiguous
+    /// (t.ex. 🖼 U+1F5BC eller ⚙ U+2699) mäts som 1 men ritas 2 bred av
+    /// emoji-fonter — då förskjuts allt efter ikonen åt höger i UI:t.
+    #[test]
+    fn emoji_icons_are_wide() {
+        let mut samples: Vec<FileEntry> = vec![
+            entry("dir", FileType::Directory),
+            entry("link", FileType::Symlink),
+        ];
+        for ext in [
+            "rs", "png", "mp4", "mp3", "zip", "pdf", "txt", "json", "sh",
+            "py", "js", "c", "exe", "unknown",
+        ] {
+            samples.push(entry(&format!("f.{}", ext), FileType::File));
+        }
+        for e in &samples {
+            let icon = e.icon();
+            assert_eq!(
+                UnicodeWidthStr::width(icon), 2,
+                "ikonen {:?} (för {:?}) är inte EAW Wide — den kommer \
+                 förskjuta raden åt höger i terminaler med emoji-font",
+                icon, e.name
+            );
+        }
+    }
+
+    /// ASCII-fallback-ikonerna ska alltid vara exakt 3 tecken ([/],
+    /// [s], ...) så att kolumnerna ligger fast i ASCII-läge.
+    #[test]
+    fn ascii_icons_are_three_cols() {
+        let e = entry("f.rs", FileType::File);
+        assert_eq!(UnicodeWidthStr::width(e.icon_ascii()), 3);
+        let d = entry("dir", FileType::Directory);
+        assert_eq!(UnicodeWidthStr::width(d.icon_ascii()), 3);
+    }
+}