Thread JaxiteWord keys through context generation and fix emitted ciphertext ops

[Zohaib58]

Change jaxiteword.gen_params to take public, secret, and evaluation keys, and
emit them into the generated ckks.CKKSParameters. Update the crypto-context
configuration pass so __generate_crypto_context accepts those three keys and
__configure_crypto_context only takes the crypto context.

Teach LWE-to-JaxiteWord lowering to add crypto context/eval-key arguments to
functions with crypto-typed arguments, update func.call operands for converted
callees, and lower CKKS rotations when a dynamic shift is defined by an arith
constant.

Rework the JaxiteWord Python emitter around tiled Polynomial values:

• emit func.call operations
• add _ensure_poly and _assign_poly helpers
• normalize ciphertext operands before add/sub/mul/square/rotate/rescale/decrypt
• use he_mul[level].mul for relined multiplication
• emit he_rescale for modulus reduction across levels
• implement plaintext add/sub against the c0 limb
• generate rotation keys via key_gen.gen_rotation_key
• store key material in generated CKKS params instead of mutating program init

Update JaxiteWord emitter/configure-context FileCheck tests and add 8x8 matvec
MLIR/Python artifacts for validating the emitted JaxiteWord path.