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/src/beads_mcp/tools.py

@@ -7,7 +7,7 @@ import subprocess
 import sys
 from contextvars import ContextVar
 from functools import lru_cache
-from typing import Annotated, TYPE_CHECKING
+from typing import Annotated, Any, TYPE_CHECKING
 
 from .bd_client import create_bd_client, BdClientBase, BdError
 
@@ -516,7 +516,7 @@ async def beads_blocked() -> list[BlockedIssue]:
     return await client.blocked()
 
 
-async def beads_inspect_migration() -> dict:
+async def beads_inspect_migration() -> dict[str, Any]:
     """Get migration plan and database state for agent analysis.
     
     AI agents should:
@@ -531,7 +531,7 @@ async def beads_inspect_migration() -> dict:
     return await client.inspect_migration()
 
 
-async def beads_get_schema_info() -> dict:
+async def beads_get_schema_info() -> dict[str, Any]:
     """Get current database schema for inspection.
     
     Returns tables, schema version, config, sample issue IDs, and detected prefix.
@@ -543,7 +543,7 @@ async def beads_get_schema_info() -> dict:
 
 async def beads_repair_deps(
     fix: Annotated[bool, "If True, automatically remove orphaned dependencies"] = False,
-) -> dict:
+) -> dict[str, Any]:
     """Find and optionally fix orphaned dependency references.
     
     Scans all issues for dependencies pointing to non-existent issues.
@@ -560,7 +560,7 @@ async def beads_repair_deps(
 
 async def beads_detect_pollution(
     clean: Annotated[bool, "If True, delete detected test issues"] = False,
-) -> dict:
+) -> dict[str, Any]:
     """Detect test issues that leaked into production database.
     
     Detects test issues using pattern matching:
@@ -578,7 +578,7 @@ async def beads_detect_pollution(
 async def beads_validate(
     checks: Annotated[str | None, "Comma-separated list of checks (orphans,duplicates,pollution,conflicts)"] = None,
     fix_all: Annotated[bool, "If True, auto-fix all fixable issues"] = False,
-) -> dict:
+) -> dict[str, Any]:
     """Run comprehensive database health checks.
     
     Available checks: