feat(management): implement dm_authorize and dm_connect procedures

[kewde]

Description

• Protocol API refactor: simple procedures (dm_restart, nm_individual_address_check, nm_individual_address_read, etc.) now take a conn: P2PConnection directly — callers own the connection lifecycle. Complex
  procedures that need to open/close their own connections keep ConnectionManager / Broadcaster signatures. Legacy wrappers are preserved to maintain backwards compatibility.
• New protocols.py: introduces P2PConnection, ConnectionManager, and Broadcaster as typing.Protocol classes, giving a clean, mockable interface for all procedure implementations.
• dm_authorize (KNX 03.05.02 §3.5): implements dmp_authorize_r_co (authorize with a single key) and dmp_authorize2_r_co (try free access first, fall back to client key, re-authorize if free access was
  better). Full test coverage including the equal-level edge case.
• dm_connect (KNX 03.05.02 §3.2.1): reads Device Descriptor Type 0 on an established connection to confirm it is live, returning the mask version. The transport-layer connect (T_Connect) is handled by the
  framework.

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Code quality improvements to existing code or addition of tests

Checklist

• The documentation has been adjusted accordingly
• Tests have been added that prove the fix is effective or that the feature works
• The changes are documented in the changelog (docs/changelog.md)