CRITICAL SECURITY VULNERABILITY: The deny rule matching is vulnerable to whitespace bypass. Because normalize_command only trims and lowercases the command without normalizing internal whitespace, a command like "git status" (with multiple spaces) will not match the deny rule "git status", allowing users to bypass the execution policy.

To fix this, normalize_command (at line 446) should be updated to normalize all internal whitespace (e.g., by splitting on whitespace and joining with a single space).

Additionally, we can optimize the prefix matching to avoid allocating a new String via format! on every check by checking if the character immediately following the prefix is a space.

        if let Some(rule) = denied_prefixes.iter().find(|rule| {
            let norm_rule = normalize_command(rule);
            normalized == norm_rule
                || (normalized.starts_with(&norm_rule)
                    && normalized.as_bytes().get(norm_rule.len()) == Some(&b' '))
        }) {

The mapping for "never" and "deny" config values to AskForApproval::OnRequest is a logical contradiction. OnRequest always prompts the user for approval, whereas "never"/"deny" should forbid/reject commands that require approval without prompting. They should be mapped to AskForApproval::Never instead.

Additionally, the runtime lock is acquired before reading the config. Holding the runtime lock across the .await of state.config.read() can cause unnecessary lock contention on the runtime Mutex. Although we cannot easily move the lock acquisition in this suggestion because the lock line is outside the diff, you should refactor this handler to read the config and resolve approval_mode before locking runtime.

We can optimize the prefix matching to avoid allocating a new String via format! on every check by checking if the character immediately following the prefix is a space.

        command_norm == pattern_norm
            || (command_norm.starts_with(&pattern_norm)
                && command_norm.as_bytes().get(pattern_norm.len()) == Some(&b' '))

While reviewing the fuzzy matching logic, we noticed that the subsequent loop (outside this diff) defines search_range by allocating a Vec via collect() on every iteration of fuzz (up to 50 times per hunk). This can be completely avoided by iterating directly over min..=max (which naturally handles fuzz == 0 as start_idx..=start_idx without any special case). Consider refactoring that loop to avoid these unnecessary allocations.