Add a nest-profiler collector

Wire a single @eleven-labs/nest-profiler-* collector into an app whose core ProfilerModule is already set up. The references/collectors-matrix.md index maps a dependency to its collector and points at the family reference with the full options, snippet, gotcha and the question(s) to ask.

Core profiler not set up yet (no @eleven-labs/nest-profiler dependency, no ProfilerModule in the codebase)? → use the setup-nest-profiler skill instead; it installs the core and can add collectors in the same pass. A collector alone does nothing without the core.

Workflow