fix(mcp): support custom issue types and statuses (#1023)

Change IssueType and IssueStatus from Literal to str to support
custom types configured via:
  bd config set types.custom "agent,molecule,event"
  bd config set status.custom "awaiting_review,awaiting_testing"

The CLI handles validation of these values against the configured
options. The MCP layer is just a transport and shouldn't re-validate
what the CLI already validates.

This fixes Pydantic validation errors when listing issues that have
custom types like 'event', 'molecule', or 'agent'.

Built-in types: bug, feature, task, epic, chore
Built-in statuses: open, in_progress, blocked, deferred, closed

integrations/beads-mcp/uv.lock

@@ -76,7 +76,7 @@ wheels = [
 
 [[package]]
 name = "beads-mcp"
-version = "0.34.0"
+version = "0.47.0"
 source = { editable = "." }
 dependencies = [
     { name = "fastmcp" },