agent: Use current shell (#28470)

Release Notes:

- agent: Replace `bash` tool with `terminal` tool which uses the current
shell

---------

Co-authored-by: Bennet <bennet@zed.dev>
Co-authored-by: Antonio <antonio@zed.dev>

crates/migrator/src/migrations/m_2025_04_15/settings.rs

@@ -0,0 +1,29 @@
+use std::ops::Range;
+use tree_sitter::{Query, QueryMatch};
+
+use crate::MigrationPatterns;
+use crate::patterns::SETTINGS_ASSISTANT_TOOLS_PATTERN;
+
+pub const SETTINGS_PATTERNS: MigrationPatterns = &[(
+    SETTINGS_ASSISTANT_TOOLS_PATTERN,
+    replace_bash_with_terminal_in_profiles,
+)];
+
+fn replace_bash_with_terminal_in_profiles(
+    contents: &str,
+    mat: &QueryMatch,
+    query: &Query,
+) -> Option<(Range<usize>, String)> {
+    let tool_name_capture_ix = query.capture_index_for_name("tool_name")?;
+    let tool_name_range = mat
+        .nodes_for_capture_index(tool_name_capture_ix)
+        .next()?
+        .byte_range();
+    let tool_name = contents.get(tool_name_range.clone())?;
+
+    if tool_name != "bash" {
+        return None;
+    }
+
+    Some((tool_name_range, "terminal".to_string()))
+}