feat: add create cluster tests

.claude/skills/rust-style/SKILL.md

@@ -61,16 +61,25 @@ let x = a.checked_add(b).ok_or(Error::Overflow)?;
 
 ## Casts
 
-No lossy or unchecked casts — use fallible conversions:
+**Never use `as` for numeric type conversions** — use fallible conversions with `try_from`:
 
 ```rust
-// Bad
+// Bad - will cause clippy errors
 let x = value as u32;
+let y = some_usize as u64;
 
-// Good
+// Good - use try_from with proper error handling
 let x = u32::try_from(value)?;
+let y = u64::try_from(some_usize).expect("message explaining why this is safe");
 ```
 
+Rules:
+
+- Always use `TryFrom`/`try_from` for numeric conversions between different types
+- Handle conversion failures explicitly (either with `?` or `expect` with justification)
+- The only acceptable use of `expect` is when the conversion is guaranteed to succeed (e.g., `usize` to `u64` on 64-bit platforms)
+- Clippy will error on unchecked `as` casts: `cast_possible_truncation`, `cast_possible_wrap`, `cast_sign_loss`
+
 ---
 
 ## Async / Tokio