Release v0.2.0

Added

• IoT Client — Data Point (DP) management layer (modules/iot-client/include/iot_dp.h).
  Sits on top of the existing transport: uplink reuses iot_client_publish(), downlink is
  intercepted on the iot_client_process() receive path — no new crypto path, threads, or timers.
  • Schema registry with typed validation (type / range / maxlen / enum) and a per-DP dirty
    bit; an empty or invalid schema falls back to loose pass-through mode.
  • Uplink reporting: iot_dp_report (single) and iot_dp_report_all_dirty /
    iot_dp_report_all (batched), guarded by the MQTT packet budget
    (OPRT_DP_PAYLOAD_TOO_LARGE).
  • Downlink protocol-5 DP-set dispatch with a per-DP change callback.
  • Persistence mechanism (the application decides when/where): iot_dp_dump_json,
    iot_dp_validate_json (strict) and iot_dp_restore_json (lenient); RAW DPs are reported
    uplink but never persisted.
  • Non-destructive schema upgrade via iot_dp_schema_check_update() (existing values kept,
    new DPs defaulted).
  • DP access mode (ro/rw/wr) from the product schema is treated as a cloud-side hint
    and is not enforced by the device SDK — the device may set/report any DP.
• POSIX dp_management_demo example demonstrating the DP layer end to end (connect,
  restore, report, downlink, persist).
• MCP mcp_example example demonstrating MCP tool integration with the agentic-kit
  framework.