Improve global search: Add diffing from results with query highlighting

Users can now open a diff for a specific search hit directly from the global search results. The original search query will be highlighted within the diff view, making it easier to locate the relevant changes.

Additionally, add `--no-textconv` to git commands used in search and diff operations. This prevents failures when git encounters binary files that textconv drivers might otherwise attempt to process.

src-tauri/src/git.rs

@@ -1338,6 +1338,10 @@ fn search_candidate_commits(
             OsString::from("--all"),
             OsString::from("--reverse"),
             OsString::from("--format=%H"),
+            // Skip textconv diff drivers so git does not extract binary files
+            // (e.g. .docx / Office temp "~$" lock files) to temp files, which can
+            // fail with "unsupported filetype" and abort the whole search.
+            OsString::from("--no-textconv"),
         ];
         if !case_sensitive {
             args.push(OsString::from("-i"));
@@ -1447,7 +1451,7 @@ fn first_added_match_line(
     check_search_cancelled(cancellation)?;
     let output = run_git_with_paths_cancellable(
         repo,
-        &["diff", "--unified=0", parent, commit],
+        &["diff", "--no-textconv", "--unified=0", parent, commit],
         &[file.to_string()],
         cancellation,
         "Git-Diff fuer Suchtreffer fehlgeschlagen",