ci(actions): add Gitea Actions ci+release workflows + fix ruff findings

- .gitea/workflows/ci.yml: ruff + matrix pytest on 3.10/3.11/3.12
  on push and PR to main; concurrency cancels superseded runs
- .gitea/workflows/release.yml: gate (ruff + pytest) + build sdist/wheel
  on tag 'v*', uploads via actions/upload-artifact@v4
- README.md: add ci and version badges right under H1
- src/viandante/cli.py: drop unused prompt_toolkit.patch_stdout import
- tests/test_deadsouls.py: add missing RoomBlock import (F821)
- tests/test_logger.py: drop unused local 'raw' in unicode test
- tests/test_mapper.py: rename unused locals to _a/_b/_c (F841) to
  preserve intent (B has 's' back-edge; C is orphan)

README.md

@@ -1,5 +1,8 @@
 # viandante
 
+[![ci](http://192.168.0.183:8085/truetype/viandante/badges/ci/main.svg)](http://192.168.0.183:8085/truetype/viandante/actions?workflow=ci)
+[![version](https://img.shields.io/badge/version-v0.2.0-blue)](http://192.168.0.183:8085/truetype/viandante/releases/tag/v0.2.0)
+
 `viandante` ospita un **client MUD CLI** pensato per collegarsi a un MUD
 LP‑MUD basato sul driver **FluffOS** (per esempio **Dead Souls**, libreria
 3.8.6). Il client parla telnet con estensioni standard: `ECHO`, `NAWS`,