feat(algorithms): add Paes (Pareto Archived Evolution Strategy)

A readable v1 PAES (spec §12.2):

- Single starting decision from the initializer.
- Each iteration mutates the current decision via the Variation operator,
  evaluates the child, and pareto_compares to the current.
- Dominating children become current; for non-dominated comparisons we
  move to the child (acceptable v1 behavior per spec).
- Both current and child are inserted into a ParetoArchive truncated
  to `archive_size` (simple tail-truncation in v1).

The final result returns the archive as both `population` and
`pareto_front`. Tests verify the archive never exceeds
`archive_size`.

src/algorithms/mod.rs

@@ -1,5 +1,7 @@
 //! Built-in reference optimizers.
 
+pub mod paes;
 pub mod random_search;
 
+pub use paes::*;
 pub use random_search::*;