Add Avnu paymaster and VRF integration (#399)

Depends on #417

Adds sidecar integration for `paymaster-service` and `vrf-server`, including CLI/config flags, bootstrap, VRF wrapping in cartridge outside execution, and paymaster profile generation with Avnu pricing. Removes custom katana paymaster/VRF crates, updates Docker to install sidecar binaries from `.tool-versions`, refreshes spec, trims the release workflow, derives a u64 VRF secret from the configured account key for `vrf-server` compatibility, and fixes paymaster/VRF CLI arg ids/defaults to avoid startup crashes. Adds unit tests for sidecar helpers and VRF seed/parsing to improve coverage. Tests: `cargo check -p katana-node --features cartridge`, `cargo test -p katana-node --features cartridge`, `cargo test -p katana-rpc-server --features cartridge --lib`, `cargo test -p katana-rpc-server --features cartridge --test paymaster_proxy`, `cargo test -p katana-cli --features cartridge`.

**Paymaster service**:
https://github.com/avnu-labs/paymaster/tree/main/crates/paymaster-service
**VRF Service**: https://github.com/cartridge-gg/vrf/tree/main/server

---------

Co-authored-by: Ammar Arif <kariy@users.noreply.github.com>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Ammar Arif <evergreenkary@gmail.com>

Author: 3 people

.github/workflows/release.yml

@@ -208,13 +208,13 @@ jobs:
         if: ${{ matrix.job.native_build == false }}
         shell: bash
         run: |
-          cargo build --bin katana --profile performance --target ${{ matrix.job.target }}
+          cargo build -p katana --bin katana --profile performance --target ${{ matrix.job.target }}
 
       - name: Build binary ( w/ cairo-native )
         if: ${{ matrix.job.native_build == true }}
         shell: bash
         run: |
-          cargo build --bin katana --profile performance --features native --target ${{ matrix.job.target }}
+          cargo build -p katana --bin katana --profile performance --features native --target ${{ matrix.job.target }}
 
       - name: Archive binaries
         id: artifacts

.gitmodules

@@ -12,9 +12,12 @@
 	path = crates/explorer/ui
 	url = https://github.com/cartridge-gg/explorer
 	branch = main
-[submodule "contracts/vrf"]
-	path = contracts/vrf
-	url = https://github.com/cartridge-gg/vrf
 [submodule "crates/cartridge/controller"]
 	path = crates/cartridge/controller
 	url = https://github.com/cartridge-gg/controller-rs.git
+[submodule "crates/contracts/contracts/vrf"]
+	path = crates/contracts/contracts/vrf
+	url = https://github.com/cartridge-gg/vrf.git
+[submodule "crates/contracts/contracts/avnu"]
+	path = crates/contracts/contracts/avnu
+	url = https://github.com/avnu-labs/paymaster

.tool-versions

@@ -1,2 +1,4 @@
 scarb 2.15.0
 katana 1.7.0
+vrf 0.3.1
+paymaster 0.2.3