Implement kaya-rbcs: simplified RBCS clone on the Kaya framework

- KayaApp with GET/PUT recursive routes backed by memcached (aiomcache)
- env-based configuration, metadata-aware value encoding, key prefix/digest
- Granian RSGI launcher (rbcs-server / python -m kaya_rbcs)
- pinned requirements via pip-compile, alpine:3.24 Dockerfile with healthcheck
- offline tests using an in-process fake memcached
- Gitea Actions workflow to build and push the multi-arch Docker image

pyproject.toml

@@ -0,0 +1,53 @@
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "kaya-rbcs"
+dynamic = ["version"]
+description = "Simplified clone of RBCS (Remote Build Cache Server) built on the Kaya web framework"
+readme = "README.md"
+requires-python = ">=3.10"
+license = { text = "MIT" }
+classifiers = [
+    'Development Status :: 3 - Alpha',
+    'Topic :: Utilities',
+    'Intended Audience :: Developers',
+    'Environment :: Console',
+    'Programming Language :: Python :: 3',
+]
+
+dependencies = [
+    "kaya-core",
+    "aiomcache",
+]
+
+[project.optional-dependencies]
+server = [
+    "kaya-rsgi",
+    "granian",
+]
+dev = [
+    "httpx",
+    "mypy",
+]
+
+[project.scripts]
+rbcs-server = "kaya_rbcs:main"
+
+[tool.setuptools.packages.find]
+where = ["src"]
+namespaces = true
+
+[tool.mypy]
+python_version = "3.12"
+disallow_untyped_defs = true
+show_error_codes = true
+no_implicit_optional = true
+warn_return_any = true
+warn_unused_ignores = true
+strict = true
+exclude = ["tests"]
+
+[tool.setuptools.dynamic]
+version = { attr = "kaya_rbcs.__version__" }