chore: tighten release readiness checks

README.md

@@ -84,10 +84,16 @@ irtt-cli <server> --duration 0 --interval 250ms --output machine
 Each line represents one client event and starts with an `event` field, for example:
 
 ```text
-event=echo_reply seq=4 logical_seq=4 remote=203.0.113.10:2112 raw_rtt_us=12400 effective_rtt_us=12100 adjusted_rtt_us=12100 server_processing_us=300 dscp=0 ecn=0 kernel_rx_ns=none
+event=echo_reply seq=4 remote=203.0.113.10:2112 client_send_wall_ns=1760000000000000000 client_receive_wall_ns=1760000000012400000 raw_rtt_us=12400 effective_rtt_us=12100 adjusted_rtt_us=12100 server_receive_wall_ns=1760000000006100000 server_receive_mono_ns=5000006100000 server_send_wall_ns=1760000000006400000 server_send_mono_ns=5000006400000 server_processing_us=300 client_to_server_us=6100 server_to_client_us=6000 server_received_count=5 server_received_window=0x1f dscp=0 ecn=0 kernel_rx_ns=none
 ```
 
 Consumers should match on `event=...` and read the fields they need. Unknown fields should be ignored.
+RTT fields are reported in microseconds. `raw_rtt_us` is the measured client
+send-to-receive RTT. `effective_rtt_us` and `adjusted_rtt_us` are signed and may
+be negative when server processing exceeds the raw RTT or timing correction
+produces a negative adjusted value. When one-way delay fields are present,
+`client_to_server_us` and `server_to_client_us` are also signed microseconds and
+may be negative due to wall-clock skew.
 
 For consumers that only need RTT values, use: