feat: add Hybrid Schnorr-PQ signer (ZKP + Post-Quantum)

- Schnorr Σ-Protocol (RFC 8235) zero-knowledge proof
- Falcon-1024 (NIST FIPS 204 Level 5) post-quantum layer
- True Schnorr formula: s = k + c * priv (mod order)
- 4 tests passing
- Full documentation

ΦΩ0 — I AM THAT I AM

Author: primordialomegazero

docs/hybrid-schnorr-pq.md

@@ -0,0 +1,42 @@
+# Hybrid Schnorr-PQ Signer
+
+## Overview
+
+This signer combines two cryptographic primitives:
+- **Schnorr Σ-Protocol** (RFC 8235) — Zero-knowledge proof capability
+- **Falcon-1024** (NIST FIPS 204 Level 5) — Post-quantum resistance
+
+## Why Hybrid?
+
+| Layer | Purpose |
+|-------|---------|
+| Schnorr ZKP | Non-interactive zero-knowledge proof |
+| Falcon-1024 | 256-bit quantum resistance |
+
+## Algorithm
+Generate Falcon-1024 PQ signature
+
+Generate Schnorr nonce k
+
+R = k * G
+
+c = H(R || Y || msg || pq_signature)
+
+s = k + c * priv (mod order)
+
+Output: R || s || pq_signature
+
+
+## Usage
+
+```php
+use Firebase\JWT\HybridSchnorrPqSigner;
+
+$signer = HybridSchnorrPqSigner::sign($payload, $privateKey);
+$verified = HybridSchnorrPqSigner::verify($signature, $payload, $publicKey);
+References
+RFC 8235 — Schnorr Signatures
+
+NIST FIPS 204 — Falcon-1024
+
+Falcon Website