Submit worker count. Do not route metrics thru ext

[cataphract]

Description

• Appsec helper submits per-service worker count
• This all the other existing telemetry metrics that the helper generates are now submitted directly to sidecar, rather than going through the extension.

See also DataDog/libdatadog#1400

[pr-commenter]

Benchmarks [ appsec ]

Benchmark execution time: 2025-12-12 19:25:00

Comparing candidate commit 1d00e73 in PR branch glopes/sidecar-ffi-tel-metrics with baseline commit 14dc0a4 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 12 metrics, 0 unstable metrics.

[pr-commenter]

Benchmarks [ tracer ]

Benchmark execution time: 2025-12-12 19:54:20

Comparing candidate commit 1d00e73 in PR branch glopes/sidecar-ffi-tel-metrics with baseline commit 14dc0a4 in branch master.

Found 2 performance improvements and 2 performance regressions! Performance is the same for 190 metrics, 0 unstable metrics.

scenario:ComposerTelemetryBench/benchTelemetryParsing

• 🟩 execution_time [-1452.634ns; -547.366ns] or [-12.523%; -4.719%]

scenario:MessagePackSerializationBench/benchMessagePackSerialization

• 🟥 execution_time [+3.761µs; +5.599µs] or [+3.599%; +5.358%]

scenario:MessagePackSerializationBench/benchMessagePackSerialization-opcache

• 🟥 execution_time [+5.841µs; +6.679µs] or [+5.590%; +6.392%]

scenario:TraceSerializationBench/benchSerializeTrace

• 🟩 execution_time [-39.252µs; -26.148µs] or [-8.846%; -5.892%]