test(backend): Add pytest testing infrastructure

- Add pytest, pytest-asyncio, pytest-mock to dev dependencies
- Configure pytest in pyproject.toml with async support
- Create tests directory structure with conftest.py
- Set up unit test framework for connector testing
- Enable automated testing for backend components

surfsense_backend/uv.lock

@@ -2578,6 +2578,15 @@ wheels = [
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 ]
 
+[[package]]
+name = "iniconfig"
+version = "2.3.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/72/34/14ca021ce8e5dfedc35312d08ba8bf51fdd999c576889fc2c24cb97f4f10/iniconfig-2.3.0.tar.gz", hash = "sha256:c76315c77db068650d49c5b56314774a7804df16fee4402c1f19d6d15d8c4730", size = 20503 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/cb/b1/3846dd7f199d53cb17f49cba7e651e9ce294d8497c8c150530ed11865bb8/iniconfig-2.3.0-py3-none-any.whl", hash = "sha256:f631c04d2c48c52b84d0d0549c99ff3859c98df65b3101406327ecc7d53fbf12", size = 7484 },
+]
+
 [[package]]
 name = "isodate"
 version = "0.7.2"
@@ -5549,6 +5558,47 @@ dependencies = [
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/12/a0/d0638470df605ce266991fb04f74c69ab1bed3b90ac3838e9c3c8b69b66a/Pysher-1.0.8.tar.gz", hash = "sha256:7849c56032b208e49df67d7bd8d49029a69042ab0bb45b2ed59fa08f11ac5988", size = 9071 }
 
+[[package]]
+name = "pytest"
+version = "9.0.2"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "colorama", marker = "sys_platform == 'win32'" },
+    { name = "iniconfig" },
+    { name = "packaging" },
+    { name = "pluggy" },
+    { name = "pygments" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/d1/db/7ef3487e0fb0049ddb5ce41d3a49c235bf9ad299b6a25d5780a89f19230f/pytest-9.0.2.tar.gz", hash = "sha256:75186651a92bd89611d1d9fc20f0b4345fd827c41ccd5c299a868a05d70edf11", size = 1568901 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/3b/ab/b3226f0bd7cdcf710fbede2b3548584366da3b19b5021e74f5bde2a8fa3f/pytest-9.0.2-py3-none-any.whl", hash = "sha256:711ffd45bf766d5264d487b917733b453d917afd2b0ad65223959f59089f875b", size = 374801 },
+]
+
+[[package]]
+name = "pytest-asyncio"
+version = "1.3.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "pytest" },
+    { name = "typing-extensions", marker = "python_full_version < '3.13'" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/90/2c/8af215c0f776415f3590cac4f9086ccefd6fd463befeae41cd4d3f193e5a/pytest_asyncio-1.3.0.tar.gz", hash = "sha256:d7f52f36d231b80ee124cd216ffb19369aa168fc10095013c6b014a34d3ee9e5", size = 50087 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/e5/35/f8b19922b6a25bc0880171a2f1a003eaeb93657475193ab516fd87cac9da/pytest_asyncio-1.3.0-py3-none-any.whl", hash = "sha256:611e26147c7f77640e6d0a92a38ed17c3e9848063698d5c93d5aa7aa11cebff5", size = 15075 },
+]
+
+[[package]]
+name = "pytest-mock"
+version = "3.15.1"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "pytest" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/68/14/eb014d26be205d38ad5ad20d9a80f7d201472e08167f0bb4361e251084a9/pytest_mock-3.15.1.tar.gz", hash = "sha256:1849a238f6f396da19762269de72cb1814ab44416fa73a8686deac10b0d87a0f", size = 34036 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/5a/cc/06253936f4a7fa2e0f48dfe6d851d9c56df896a9ab09ac019d70b760619c/pytest_mock-3.15.1-py3-none-any.whl", hash = "sha256:0a25e2eb88fe5168d535041d09a4529a188176ae608a6d249ee65abc0949630d", size = 10095 },
+]
+
 [[package]]
 name = "python-bidi"
 version = "0.6.6"
@@ -6610,6 +6660,10 @@ dependencies = [
 
 [package.dev-dependencies]
 dev = [
+    { name = "httpx" },
+    { name = "pytest" },
+    { name = "pytest-asyncio" },
+    { name = "pytest-mock" },
     { name = "ruff" },
 ]
 
@@ -6676,7 +6730,13 @@ requires-dist = [
 ]
 
 [package.metadata.requires-dev]
-dev = [{ name = "ruff", specifier = ">=0.12.5" }]
+dev = [
+    { name = "httpx", specifier = ">=0.28.0" },
+    { name = "pytest", specifier = ">=8.0.0" },
+    { name = "pytest-asyncio", specifier = ">=0.24.0" },
+    { name = "pytest-mock", specifier = ">=3.14.0" },
+    { name = "ruff", specifier = ">=0.12.5" },
+]
 
 [[package]]
 name = "sympy"