Close the host-testable gaps named in Phase 6 of STABILITY_TESTABILITY_HANDOFF.md
by moving the last inline decision logic into the pure, host-tested policy seams:
- WiFi STA reconnect backoff: extract the inline ladder + wrap-safe timing from
handleWiFiConnection() into MQTTConnectionPolicy::{wifiReconnectBackoffMs,
wifiReconnectDue,nextWifiBackoffAttempt}. Behavior-preserving (elapsedMs is the
wrap-safe form of the old ULONG_MAX branch); ladder/clamp/attempt-cap unchanged.
- Publication outcome pairing: name the (packet, raw) -> delivered contract as
MQTTPacketQueuePolicy::queuedPacketPublished() and wire both queue-drain sites;
partial success = completed, not retried.
- Freeze MQTTPublicationType enum values in a test (the bridge-side MQTTMessageType
alignment is already enforced by a compile-time static_assert).
Adds host tests for all three (exact boundaries + millis() rollover). Native suite
green (13 dirs); non-PSRAM observer firmware smoke build compiles.
WebConfig batch/reboot/stop state-machine extraction and queue-orchestration
coverage remain open (tracked in the Phase 6 status).
Replace direct JSON construction in MQTTMessageBuilder with calls to
MQTTPayloadBuilder for building status, packet, and raw messages.
This change improves code maintainability and reduces duplication by
centralizing message formatting logic. Additionally, update platformio.ini
to include ArduinoJson dependency for JSON handling.
agessaman