terminal: Prevent [] from being sanitized into clickable file link (#20386)

This PR prevents `[]` from being sanitized into an empty string and thus
becoming a "valid", clickable file link in the integrated terminal.


Whenever you type `[]` into the terminal and hover over it while
pressing `cmd`, an empty popup appears and the cursor indicates that
this is a clickable element. Once you click on the brackets, the
worktree root is selected and focused within the file picker.

<img width="87" alt="grafik"
src="https://github.com/user-attachments/assets/01790323-88be-4373-a1ec-a345bcf2521e">


This is because in #2906 support was added for sanititzing file links
like `[/some/path/[slug].tsx]` to `/some/path/[slug].tsx`. In the case
`[]` where an empty string is returned from the sanitation, the string
is considered a valid file path and thus `[]` becomes a valid and
clickable navigation target.

Given that this an edge-case just for this specific one set of brackets
and otherwise no empty strings are matched from the regexes `URL_REGEX`
and `WORD_REGEX`, it seemed that this was the best place to fix this
bug.

Release Notes:

- `[]` is no longer considered a clickable link in the terminal

crates/terminal/src/terminal.rs

@@ -924,8 +924,12 @@ impl Terminal {
                 } else if let Some(word_match) = regex_match_at(term, point, &mut self.word_regex) {
                     let file_path = term.bounds_to_string(*word_match.start(), *word_match.end());
 
-                    let (sanitized_match, sanitized_word) =
-                        if file_path.starts_with('[') && file_path.ends_with(']') {
+                    let (sanitized_match, sanitized_word) = if file_path.starts_with('[')
+                        && file_path.ends_with(']')
+                        // this is to avoid sanitizing the match '[]' to an empty string,
+                        // which would be considered a valid navigation target
+                        && file_path.len() > 2
+                    {
                         (
                             Match::new(
                                 word_match.start().add(term, Boundary::Cursor, 1),