Harden USB logging and persist watchdog events in management reports

docs/management_decoder.md

@@ -1,6 +1,6 @@
 # Management report decoder
 
-Paste MGR1 management-report payloads or complete GroupData packets from a
+Paste MGR1, MGR2, or MGR3 management-report payloads or complete GroupData packets from a
 packet analyzer to read a radio's public management information. Everything,
 including password authentication and ACL decryption, happens locally in this
 browser. The report, password, and candidate public key are never uploaded.
@@ -13,13 +13,13 @@ by someone who does not know that password.
 ## Decode a management report
 
 <div class="management-tool" data-management-decoder>
-  <label for="management-packet-input">MGR1 payload or complete GroupData packet hex</label>
+  <label for="management-packet-input">MGR1/MGR2/MGR3 payload or complete GroupData packet hex</label>
   <textarea
     id="management-packet-input"
     data-role="input"
     spellcheck="false"
     autocomplete="off"
-    placeholder="Paste analyzer Raw Data, canonical MGR1 payload hex, or one MQTT raw value per line"
+    placeholder="Paste analyzer Raw Data, canonical MGR1/MGR2/MGR3 payload hex, or one MQTT raw value per line"
     aria-describedby="management-packet-help"
   ></textarea>
   <p class="management-help" id="management-packet-help">
@@ -31,7 +31,7 @@ by someone who does not know that password.
   <label for="management-password-input">Management password <span>(optional for public fields; required for ACLs)</span></label>
   <input id="management-password-input" data-role="password" type="password" autocomplete="new-password">
   <p class="management-help">
-    The password remains in this page only. The decoder derives the MGR1 AES-SIV key in
+    The password remains in this page only. The decoder derives the management AES-SIV key in
     your browser and does not send it anywhere.
   </p>
 
@@ -67,9 +67,10 @@ by someone who does not know that password.
 ## What the decoder accepts
 
 - Complete `PAYLOAD_TYPE_GRP_DATA` (`0x06`) analyzer/MQTT packet hex. It checks
-  the MeshCore route header, encoded path length, MGR1 page bounds, and required
+  the MeshCore route header, encoded path length, version-specific page bounds, and required
   zero padding.
-- A canonical MGR1 payload beginning with `4D475231` (`MGR1`).
+- A canonical payload beginning with `4D475231` (`MGR1`), `4D475232` (`MGR2`),
+  or `4D475233` (`MGR3`).
 - One raw packet or canonical payload per line; duplicate observations of an
   identical page are deduplicated.
 
@@ -78,5 +79,32 @@ the report-specific fingerprints and the administrator and/or OTA-signer flags.
 It cannot turn a fingerprint back into a full key. Use the optional candidate
 field to test a specific full public key.
 
+MGR2 and MGR3 also show USB logging, host/reader connection, logger-client activity, stalled/recovering/deferred
+state, recovery stage, saved backoff, retry interval/inactive seconds, Auto qualification
+seconds, and persistence
+readiness. Unsupported observation is shown explicitly; legacy MGR1 has no
+USB block and shows it as unavailable. These values are the report-start
+snapshot, not proof that a Pi or host application is healthy. Older decoder
+copies require an update for MGR3.
+
+MGR3 additionally shows the latest USB watchdog action, reason mask and names,
+advisory node-clock timestamp, recorded-boot uptime seconds, event sequence,
+and whether the record was durably saved. Software recovery and re-enumeration
+mean attempted actions, not successful repairs. A reboot request is not proof
+that a reboot completed; a later cancellation can replace it. The node clock
+can be wrong, even when it resembles a valid date. Event uptime and sequence
+remain useful for ordering. MGR1/MGR2 do not carry this event field and show it
+as unavailable. All 36 ACL entries still fit, using up to nine MGR3 pages.
+
+Reports contain a frozen latest-event snapshot, not immediate watchdog alerts
+or a complete event history. See [USB logging watchdog](usb_logging_watchdog.md)
+for local review and persistence limitations.
+
+Host/reader connection only describes the USB link or open reader. Logger-client
+activity means recent USB stats polling within a 15-minute lease, renewed by
+the existing five-minute polls without a new registration or heartbeat command.
+The flag also requires logging enabled and a connected, unstalled USB link.
+It does not identify the client or prove MQTT delivery, disk writes, or Pi health.
+
 For the report schedule, public-field layout, cryptographic design, and the
 offline Python capture tool, see [Management reports](management_reports.md).