ci: add E2E workflow for SAR mission and crypto channel tests

Wires the existing end_to_end.rs Rust tests into CI. Tests SAR mission
simulation, ECM attack response, comms loss, signal analysis, and
post-quantum cryptographic channel establishment.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

.github/workflows/e2e.yml

@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: PMPL-1.0-or-later
+# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
+#
+# End-to-end and integration tests for robodog-ecm.
+# Tests SAR mission simulation, ECM attack, comms loss, signal analysis,
+# and post-quantum cryptographic channel establishment.
+
+name: E2E + Integration Tests
+
+on:
+  push:
+    branches: [main, master, develop]
+    paths:
+      - 'src/**'
+      - 'Cargo.toml'
+      - '.github/workflows/e2e.yml'
+  pull_request:
+    branches: [main, master]
+    paths:
+      - 'src/**'
+      - 'Cargo.toml'
+  workflow_dispatch:
+
+permissions: read-all
+
+concurrency:
+  group: e2e-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  e2e:
+    name: E2E — SAR Mission + ECM + Crypto
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5  # v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@4be9e76fd7c4901c61fb841f559994984270fce7  # stable
+
+      - name: Rust cache
+        uses: Swatinem/rust-cache@779680da715d629ac1d338a641029a2f4372abb5  # v2
+
+      - name: Run unit tests
+        run: cargo test --workspace
+
+      - name: Run E2E tests specifically
+        run: cargo test --test end_to_end -- --nocapture
+        working-directory: src/rust
+
+      - name: Run benchmarks (if present)
+        run: cargo bench --workspace 2>/dev/null || echo "No benchmarks configured yet"