Resolve unauthenticated remote DoS in quinn-proto QUIC parsing (#54)

* Resolve unauthenticated remote DoS in QUIC transport parameter parsing

Investigate quinn-proto 0.11.13 vulnerability where attacker-controlled
varints decoded with unwrap() cause panic on truncated encodings,
reachable over the network with a single unauthenticated packet.
Upgrade quinn-proto to 0.11.14 which replaces unwrap() with proper
error propagation.

* Resolve unauthenticated remote DoS in QUIC transport parameter parsing

Introduce quinn-proto 0.11.14 version floor in btlightning Cargo.toml
to force all downstream consumers to resolve the patched version.
Addresses CVE-2026-31812 where attacker-controlled varints decoded
with unwrap() cause panic on truncated encodings, reachable over the
network with a single unauthenticated packet.

Author: HudsonGraeme

Cargo.lock

@@ -14,6 +14,7 @@ name = "btlightning"
 
 [dependencies]
 quinn = "0.11"
+quinn-proto = "0.11.14"
 rustls = { version = "0.23", default-features = false, features = ["ring", "std", "logging"] }
 rcgen = "0.13"
 tokio = { version = "1.0", features = ["full"] }