docs: add guide to run SNARK tests

Author: jpraynaud

RUN-SNARK-TESTS.md

@@ -0,0 +1,67 @@
+# Running SNARK Proofs Tests
+
+This guide walks you through running SNARK proof tests for Mithril, covering both unit tests and the full end-to-end test suite.
+
+## Prerequisites
+
+- **Operating System**: Linux (Ubuntu 24.04 or later)
+- **Rust toolchain**: latest stable version
+
+## Getting Started
+
+Clone the Mithril repository:
+
+```bash
+git clone git@github.com:input-output-hk/mithril.git
+cd mithril
+```
+
+## Unit Tests
+
+Run the full workspace unit tests with the `future_snark` feature enabled:
+
+```bash
+cargo test --all-features --features future_snark
+```
+
+## End-to-End Test
+
+### Branch Setup
+
+Switch to the dedicated SNARK end-to-end test branch:
+
+```bash
+git switch jpraynaud/3107-snark-e2e-test
+```
+
+### Working Directory Configuration
+
+> **Important**: The working directory path must be kept short because the Cardano node uses local socket files with path length limitations. Use an absolute path such as the example below. **Do not** use `.` as the working directory, this could delete your entire repository.
+
+Set the working directory environment variable:
+
+```bash
+WORK_DIRECTORY=~/Desktop/mithril/artifacts
+```
+
+### Running the Test
+
+The following command compiles all required nodes and runs the end-to-end test with SNARK proofs. Expect the full process to take approximately **10 to 20 minutes** depending on your machine:
+
+```bash
+cargo build --release --features future_snark \
+  -p mithril-aggregator \
+  -p mithril-signer \
+  -p mithril-client-cli \
+  -p mithril-relay \
+  -p mithril-end-to-end \
+&& RUST_BACKTRACE=1 ./target/release/mithril-end-to-end -vvvv \
+  --bin-directory ./target/release/ \
+  --work-directory=$WORK_DIRECTORY \
+  --devnet-scripts-directory=./mithril-test-lab/mithril-devnet \
+  --mithril-era=lagrange \
+  --aggregate-signature-type=Snark \
+  --cardano-epoch-length=50 \
+  --cardano-slot-length=1.0 \
+  --mithril-run-interval 500
+```