Add Ironwood (NU6.3) payment detection support

Upgrade zcash crates to NU6.3-compatible versions and add trial
decryption for the Ironwood shielded pool alongside Orchard. This
fixes payment detection for post-activation transactions (v6 format)
which were silently ignored due to BranchId::Nu6_2 parse failures.

- zcash_primitives 0.28 → 0.29 (v6 tx format)
- orchard 0.14 → 0.15 (IronwoodDomain)
- zcash_note_encryption 0.4 → 0.4.2
- zcash_protocol 0.9 → 0.10 (BranchId::Nu6_3)
- zcash_address 0.12 → 0.13

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: kenbak wan

Cargo.lock

@@ -28,12 +28,12 @@ reqwest = { version = "0.12", features = ["json"] }
 # WebSocket client (for CipherScan real-time mempool push)
 tokio-tungstenite = { version = "0.26", features = ["native-tls"] }
 
-# Zcash crates
-zcash_primitives = { version = "0.28", default-features = false }
-zcash_note_encryption = "0.4"
-orchard = { version = "0.14", default-features = false, features = ["std"] }
-zcash_address = "0.12"
-zcash_protocol = "0.9"
+# Zcash crates (NU6.3 / Ironwood support)
+zcash_primitives = { version = "0.29", default-features = false }
+zcash_note_encryption = "0.4.2"
+orchard = { version = "0.15", default-features = false, features = ["std"] }
+zcash_address = "0.13"
+zcash_protocol = "0.10"
 
 # WebAuthn / Passkeys
 webauthn-rs = { version = "0.5", features = ["danger-allow-state-serialisation"] }