chore: set up uv, add uv.lock

Adds uv lockfile and .venv. Only runtime dep is toml; pytest added as dev dep.
Service-level dependencies (OpenAI, Gemini, Anthropic, OpenRouter APIs) are
tracked separately via the state-hub capability/service dependency system.

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

pyproject.toml

@@ -1,21 +1,26 @@
-[build-system]
-requires = ["setuptools>=42", "wheel"]
-build-backend = "setuptools.build_meta"
-
-[project]
-name = "llm-connect"
-version = "0.1.0"
-description = "Pluggable LLM adapters for OpenRouter, Gemini, OpenAI and Claude Code CLI"
-requires-python = ">=3.10"
-dependencies = [
-    "toml",
-]
-
-[project.optional-dependencies]
-dev = [
-    "pytest>=7.0",
-]
-
-[tool.setuptools.packages.find]
-where = ["."]
-include = ["llm_connect*"]
+[build-system]
+requires = ["setuptools>=42", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "llm-connect"
+version = "0.1.0"
+description = "Pluggable LLM adapters for OpenRouter, Gemini, OpenAI and Claude Code CLI"
+requires-python = ">=3.10"
+dependencies = [
+    "toml",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=7.0",
+]
+
+[tool.setuptools.packages.find]
+where = ["."]
+include = ["llm_connect*"]
+
+[dependency-groups]
+dev = [
+    "pytest>=9.0.2",
+]