Add epoch conversion hint to network-rca skill data boundaries section

Description

The network-rca skill's "Check Data Boundaries" section (around line 143) should include an explicit hint about converting Unix epoch milliseconds returned by get_data_boundaries.

Currently, there's no guidance on how to interpret the epoch timestamps, which leads to off-by-one timezone errors that silently shift the investigation window by hours.

Proposed addition — insert after the example response table (line 162), before the data rotation note:

Epoch conversion rule: get_data_boundaries returns Unix milliseconds. Always convert programmatically — never estimate or do mental math:

bash复制

python3 -c "from datetime import datetime, timezone, timedelta; ts=EPOCH_MS/1000; local=timezone(timedelta(hours=OFFSET)); print(datetime.fromtimestamp(ts, tz=local))"

Off-by-one timezone errors silently shift the investigation window by hours.

Why Is This Needed?

When an AI agent receives epoch milliseconds from get_data_boundaries, it may attempt mental math or rough estimation for timezone conversion, resulting in queries that target the wrong time window. This is a silent failure — the query succeeds but returns irrelevant or empty results, derailing the investigation. An explicit conversion rule prevents this class of errors.