Add comprehensive type annotations

- mypy.ini: expanded configuration with module-specific settings
- hookspecs.py: type annotations for hook functions
- plugins.py: typed get_plugins() return value
- recipes.py: full type annotations for parsedate, parsedatetime, jsonsplit
- utils.py: extensive type annotations including Row type alias,
  TypeTracker, ValueTracker, and all utility functions
- db.py: type annotations for Database methods (__exit__,
  ensure_autocommit_off, tracer, register_function, etc.) and
  Queryable class methods
- tests/test_docs.py: updated to match new signature display format

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

sqlite_utils/hookspecs.py

@@ -1,3 +1,6 @@
+import sqlite3
+
+import click
 from pluggy import HookimplMarker
 from pluggy import HookspecMarker
 
@@ -6,10 +9,10 @@ hookimpl = HookimplMarker("sqlite_utils")
 
 
 @hookspec
-def register_commands(cli):
+def register_commands(cli: click.Group) -> None:
     """Register additional CLI commands, e.g. 'sqlite-utils mycommand ...'"""
 
 
 @hookspec
-def prepare_connection(conn):
+def prepare_connection(conn: sqlite3.Connection) -> None:
     """Modify SQLite connection in some way e.g. register custom SQL functions"""