Add log_note execution option - #13435

What

Adds a typed Core log_note execution option for Engine, Connection, SQL statements, and per-execution options. The note appears in brackets immediately after the cache statistics badge in the statement parameter log record.

Why

Issue #7732 requests a way to tag individual SQL executions in logs without changing the SQL string or compiled cache key. This PR implements the Core portion; automatic notes for ORM eager, lazy, and deferred loaders remain a separate follow-up.

How

DefaultExecutionContext formats the effective note once, and both ordinary execution and insertmanyvalues logging paths append it after cache statistics. The option is included in synchronous, asynchronous, statement, legacy Query, and known execution-option typing surfaces. Existing log output remains unchanged when the option is absent or empty, including hidden-parameter output.

Core logging documentation and a SQLAlchemy 2.1 changelog entry are included.

Testing

• python -m pytest -n 0 test/engine/test_logging.py test/typing/test_overloads.py -q — 86 passed
• python -m mypy on the six changed source modules
• Black, zimports, flake8, and tools/format_docs_code.py --check
• Sphinx HTML build with the changed pages rebuilt under -W

Coverage includes per-execution, statement, connection, and engine scopes; empty notes; hidden parameters; and multi-batch insertmanyvalues logging.

Breaking changes

None.

Checklist

This pull request is:

• A documentation / typographical / small typing error fix
• A short code fix
• A new feature implementation
  • Includes issue add new execution option "log_note", implement for ORM queries #7732, tests, Core documentation, and a 2.1 changelog entry.