Add ss-setup TUI tool with unit tests and CI integration

Interactive whiptail/dialog TUI for server/client config generation,
systemd service management, SIP003 plugin installation, and ss:// URI
output. Includes 131 bash unit tests covering all utility functions
(validation, JSON generation, URI encoding, config round-trip parsing).
Tests run in CTest and as a dedicated GitHub Actions step.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/build.yml

@@ -39,6 +39,9 @@ jobs:
           cd build
           ctest --output-on-failure
 
+      - name: ss-setup TUI tests
+        run: bash tests/test_ss_setup.sh
+
       - name: Stress test
         run: |
           python3 tests/stress_test.py --bin build/shared/bin/ --size 10