0.10.5 — runtime-data migration (Platinum quality-scale)

No breaking changes; no user-visible behavior change. Internal
architecture cleanup only.

Migrated the last remaining runtime-data quality-scale gap (flagged as
todo in 0.10.4's Round 1 audit): every platform's async_setup_entry
(button, binary_sensor, climate, cover, event, light, number, select,
sensor, switch, valve, alarm_control_panel, update), plus
device_trigger.get_device_from_id, diagnostics.async_get_config_entry_diagnostics,
and the options flow, now read config_entry.runtime_data.session
directly instead of the legacy hass.data[DOMAIN][entry_id][...] dict.
The two entity classes that only carry an entry_id string (not the
config entry object itself — event.py's SHCScenarioEvent and
switch.py's user-defined-state switch) look the entry back up via
hass.config_entries.async_get_entry(entry_id). The parallel
hass.data[DOMAIN] population in async_setup_entry/async_unload_entry
and the now-dead DATA_SESSION/DATA_SHC/DATA_TITLE/
DATA_POLLING_HANDLER/DATA_CERT_CHECK_UNSUB constants are gone
entirely. quality_scale.yaml's runtime-data rule is done again —
this time genuinely, not the false claim Round 1 corrected. Both the
Gold and Platinum quality-scale gates pass in full for the first time.

All ~65 touched files (17 source, ~45 tests) re-verified: 2973/2973 tests
green, ruff/pylint/mypy/codespell clean.