feat(pos/facturapi): finalize Horux-to-Facturapi migration

- Normalize Facturapi key/org_id resolution (supports both cfdi_ prefixed
  tenant_config keys and short names used by invoicing_bp).
- Add CSD upload end-to-end (backend + frontend).
- Add helper scripts: setup_facturapi_orgs.py and check_facturapi_tenants.py.
- Add 20 unit tests with mocks (pos/tests/test_facturapi_service.py).
- Add CI workflow for lint + console tests on Python 3.11/3.13.
- Add pyproject.toml and requirements-dev.txt with ruff/pytest config.
- Update FASES_IMPLEMENTADAS.md with FASE 8 documentation.

Tests: 81 passing (61 console + 20 Facturapi).

pyproject.toml

@@ -0,0 +1,47 @@
+[tool.ruff]
+target-version = "py311"
+line-length = 120
+exclude = [
+    ".git",
+    "__pycache__",
+    ".pytest_cache",
+    ".venv",
+    ".venv_import",
+    "node_modules",
+    "backups",
+    "data",
+    "vehicle_database",
+]
+
+[tool.ruff.lint]
+select = [
+    "E",   # pycodestyle errors
+    "F",   # Pyflakes
+    "W",   # pycodestyle warnings
+    "I",   # isort
+    "UP",  # pyupgrade
+    "B",   # flake8-bugbear
+    "C4",  # flake8-comprehensions
+    "SIM", # flake8-simplify
+]
+ignore = [
+    "E501",  # line too long (handled by formatter)
+    "B008",  # do not perform function calls in argument defaults
+    "B905",  # zip() without strict= (Python <3.10 compat)
+]
+
+[tool.ruff.lint.pydocstyle]
+convention = "google"
+
+[tool.ruff.format]
+quote-style = "double"
+indent-style = "space"
+skip-magic-trailing-comma = false
+line-ending = "auto"
+
+[tool.pytest.ini_options]
+testpaths = ["console/tests", "pos/tests"]
+python_files = ["test_*.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = "-v --tb=short"