Pin the Rust toolchain to 1.95.0 (#57373)

## What changed

- Replace Rust `1.99.1` pins with `1.95.0` across Cargo, Bazel, CI, release workflows, and Windows setup, and update the Bazel lockfile.
- Adjust Rust APIs, borrowing, and lint-related code for the pinned toolchain, and box MCP tool dispatch to bound compiler async-layout query depth.
- Update the halfwidth sound mark snapshot and allow optional symbol hash suffixes in the code mode host package smoke test.

GitOrigin-RevId: 75460c3d0465dc601811e619bce373a4f7ff2912

codex-rs/shell-command/src/bash.rs

@@ -88,8 +88,11 @@ pub fn try_parse_word_only_commands_sequence(tree: &Tree, src: &str) -> Option<V
 
     let mut commands = Vec::new();
     for node in command_nodes {
-        let words = parse_plain_command_from_node(node, src)?;
-        commands.push(words);
+        if let Some(words) = parse_plain_command_from_node(node, src) {
+            commands.push(words);
+        } else {
+            return None;
+        }
     }
     Some(commands)
 }