Improve type safety and fix minor issues in beads-mcp

Type Safety Improvements:
- Change dict → dict[str, Any] throughout codebase for explicit typing
- Add PEP 561 py.typed marker file to export type information
- Add types-requests to dev dependencies
- Improve signal handler typing (FrameType | None)
- Improve decorator typing (Callable[..., Awaitable[T]])
- Add quickstart() abstract method to BdClientBase for interface completeness

Bug Fixes:
- Fix variable shadowing: beads_dir → local_beads_dir in bd_client.py
- Improve error handling in mail.py:_call_agent_mail() to prevent undefined error
- Make working_dir required (not Optional) in BdDaemonClient
- Remove unnecessary 'or' defaults for required Pydantic fields

Validation:
- mypy passes with no errors
- All unit tests passing
- Daemon quickstart returns helpful static text (RPC doesn't support this command)

integrations/beads-mcp/uv.lock

@@ -82,6 +82,7 @@ dev = [
     { name = "pytest-asyncio" },
     { name = "pytest-cov" },
     { name = "ruff" },
+    { name = "types-requests" },
 ]
 
 [package.metadata]
@@ -98,6 +99,7 @@ dev = [
     { name = "pytest-asyncio", specifier = ">=1.2.0" },
     { name = "pytest-cov", specifier = ">=7.0.0" },
     { name = "ruff", specifier = ">=0.14.0" },
+    { name = "types-requests", specifier = ">=2.31.0" },
 ]
 
 [[package]]
@@ -1637,6 +1639,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/77/b8/0135fadc89e73be292b473cb820b4f5a08197779206b33191e801feeae40/tomli-2.3.0-py3-none-any.whl", hash = "sha256:e95b1af3c5b07d9e643909b5abbec77cd9f1217e6d0bca72b0234736b9fb1f1b", size = 14408 },
 ]
 
+[[package]]
+name = "types-requests"
+version = "2.32.4.20250913"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "urllib3" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/36/27/489922f4505975b11de2b5ad07b4fe1dca0bca9be81a703f26c5f3acfce5/types_requests-2.32.4.20250913.tar.gz", hash = "sha256:abd6d4f9ce3a9383f269775a9835a4c24e5cd6b9f647d64f88aa4613c33def5d", size = 23113 }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/2a/20/9a227ea57c1285986c4cf78400d0a91615d25b24e257fd9e2969606bdfae/types_requests-2.32.4.20250913-py3-none-any.whl", hash = "sha256:78c9c1fffebbe0fa487a418e0fa5252017e9c60d1a2da394077f1780f655d7e1", size = 20658 },
+]
+
 [[package]]
 name = "typing-extensions"
 version = "4.15.0"