a9e7baee6a
Extends the push agent (v1.2.0) with the Netdata-style signals the operator wants: per-core CPU, per-interface network throughput and per-disk I/O (rates derived in-agent from monotonic /proc counter deltas, with counter-reset clamping), hardware temperatures (/sys/class/hwmon), memory-pressure PSI (/proc/pressure), and cached/buffers memory breakdown. All stdlib-only. Server side needs no migration — these land as additional rows in the shared PluginMetric table via _expand_sample_to_metrics. Per-resource series use a ':' in resource_name (host:net:eth0, host:core0, host:temp:Package) so the existing fleet widget's ':' filter ignores them; host-level totals/max are emitted at the bare host resource. New sample keys are optional, so older agents keep ingesting unchanged. Unit tests for the new parsers, rate/reset logic, and the expander contract. Data foundation for the Netdata-style host view (task #867). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>