server: fix edit_file crash on append at end of file (line_start -1) (#24893)
line_start -1 normalized to n+1, so append inserted at lines.begin() + n + 1,
one past end() -> heap-buffer-overflow in vector::_M_range_insert.
Normalize -1 to n (insert at end()), restrict -1 to append mode and reject it
for replace/delete instead of silently clobbering the last line. Parenthesize
the insert offset so empty-file append computes the position as int first,
avoiding a transient begin() - 1 on a null vector data pointer.
overview / pkg / ggml / sources / llama.cpp / commit