README: refresh Limitations section

Two stale bullets:
- "currently targets JAX 0.8.x" — now tested on 0.8.x, 0.9.x, and
  0.10.x; pin is jax>=0.8,<0.11.
- "effective_order is a hint, not a guarantee" — was true before the
  cross-jit propagation fix; now it's a real contract (correct prefix
  below the threshold, unspecified above), uniform across all aware
  primitives.

Pytree-primal limitation is still accurate; kept.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: thisiscam

README.md

@@ -279,9 +279,8 @@ The full correctness suite checks every supported primitive against
 ## Limitations
 
 - Pytree primal inputs are not supported (each primal must be a leaf).
-- The package depends on `jax._src` internals and currently targets
-  JAX 0.8.x.
-- `effective_order` is a hint, not a guarantee — see the caveats above.
+- The package depends on `jax._src` internals; currently tested on
+  JAX 0.8.x, 0.9.x, and 0.10.x.
 
 ## Citation