0.8.1 — Document Smoke Detector II intrusion-alarm scope

Document Smoke Detector II intrusion-alarm scope

Docs-only release. A real-hardware test by @sid3windr settled the long-open question on #174 / #322 about what the Smoke Detector II "Intrusion Alarm" switch actually does.

Findings (verified on an SD II)

• The switch (INTRUSION_ALARM_ON_REQUESTED) sounds and clears only that one detector's siren.
• It does not cascade to other smoke detectors / Twinguards.
• It raises no Bosch app notification.
• There is no local-API path to force the whole intrusion-alarm system: SurveillanceAlarm is read-only and the IDS only supports arm / disarm / mute. A generic "trigger alarm" service is therefore not feasible.

Changes

• README: Smoke Detector II now listed separately in the entity table with a footnote describing the single-device scope.
• CHANGELOG: 0.8.1 entry.
• No functional change — the 0.7.11 switch behaviour is correct as-is.