`BlindRSA.blindSign()` skips the RSAVP1 consistency check on the RSA-RAW path

`BlindRSA.blindSign()` currently takes a different code path when `supportsRSARAW` is enabled, skipping the post-sign `RSAVP1` consistency check present in the software signing path.

## Source references

- `supportsRSARAW` is an exposed platform parameter in `src/index.ts`:
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- In `src/blindrsa.ts`, the RSA-RAW path returns immediately:
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- The non-RSA-RAW path in the same function performs the expected verification and throws on mismatch:
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- The helper used by the RSA-RAW branch, `rsaRawBlingSign()`, just calls `crypto.subtle.sign(...)` and returns the result directly:
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- For comparison, `PartiallyBlindRSA` still performs the `RSAVP1`/equality check even when it uses `rsaRawBlingSign()`:
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## Issue

This means `BlindRSA.blindSign()` behaves inconsistently across implementations:

- **software path**: signs, verifies `m == RSAVP1(s)`, rejects on mismatch
- **RSA-RAW path**: returns the signer output without that verification

If the RSA-RAW backend ever returns a faulty signature, this path will propagate it to the caller instead of failing with `signing failure`.

I am intentionally keeping the claim narrow here: this issue is the missing validation step in the RSA-RAW blind-signing path, not a claim of demonstrated real-world fault injection in a specific deployment. But the code-level inconsistency is real and security-relevant.

## Suggested fix

Apply the same `RSAVP1` consistency check to the RSA-RAW result before returning it, as is already done in the non-RSA-RAW `BlindRSA` path and in `PartiallyBlindRSA`.

Start in src/blindrsa.ts at BlindRSA.blindSign(), comparing the RSA-RAW return at lines 149-152 with the verification at lines 166-178. Review rsaRawBlingSign() in src/util.ts and the corresponding check in src/partially_blindrsa.ts; done means the RSA-RAW result receives the same RSAVP1 consistency validation before it is returned.

Written by the indexing model from the issue text.