Wrap provider constructor in try/except and update TODO comment

- Move lock instance creation inside existing exception handler so a
  provider __post_init__ failure skips gracefully
- Update comment: Matter/Virtual provider filtering is a known issue
  to be fixed in a follow-up PR

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Entire-Checkpoint: 642d587af47e

Author: raman325

custom_components/lock_code_manager/config_flow.py

@@ -172,10 +172,10 @@ async def _async_get_unmanaged_codes(
                 exc_info=True,
             )
             continue
-        # Note: some providers (Matter, Virtual) only return slots already
-        # configured in a Lock Code Manager config entry, so unmanaged codes
-        # on those providers will not be detected here. This reset step is
-        # most useful for Z-Wave locks which return all occupied slots.
+        # TODO: Matter and Virtual providers currently only return slots
+        # managed by an LCM config entry. A follow-up PR will make them
+        # return all occupied slots (matching Z-Wave behavior) so unmanaged
+        # codes are detected here.
         managed_slots = {
             int(s)
             for entry in hass.config_entries.async_entries(DOMAIN)