Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/capi/src/ceval.rs`:
- Around line 118-124: `PyEval_GetLocals` is returning the frame’s locals
mapping without first synchronizing fast locals, so update the
`PyEval_GetLocals` implementation in `ceval.rs` to use the same synchronization
path as `frame.locals(vm)` before converting to a raw `PyObject`. Keep the
existing `with_vm`/`current_frame` flow, but fetch the synced locals mapping
from the frame rather than calling `frame.locals.as_object(vm)` directly so the
behavior matches CPython.
- Around line 127-150: PyEval_GetFuncName is returning borrowed string pointers
that may not be stable or NUL-terminated, especially for __name__ and cls.name()
paths. Update PyEval_GetFuncName to construct and return a stable C string
(matching the approach used by PyEval_GetFuncDesc) by converting the chosen name
into a CString or equivalent CStr-backed value before returning, and keep the
recursive bound_method_type path consistent with that same ownership model.

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/capi/src/pyframe.rs`:
- Around line 8-16: `PyFrame_GetLineNumber` currently converts the `f_lineno()`
result from `usize` to `c_int` with a blind cast, which can truncate large
values. Update the `PyFrame_GetLineNumber` implementation in `pyframe.rs` to use
a checked conversion or explicit bounds handling before returning
`core::ffi::c_int`, and keep `PyFrame_GetCode` unchanged since its ownership is
already correct.