feat: rename instrumentation to simulation

[GuillaumeLagrange]

instrumentation is still accepted as an input, but it maps to simulation internally, as we plan to phase it out.

[Copilot]

Pull Request Overview

This PR renames the "instrumentation" mode to "simulation" throughout the codebase while maintaining backward compatibility. The environment variable CODSPEED_RUNNER_MODE now accepts both "instrumentation" (deprecated) and "simulation" (preferred), with both values mapping to the same "simulation" mode internally.

Key Changes:

• Core mode handling updated to accept both "instrumentation" and "simulation" values for backward compatibility
• File renames: instrumented.ts → simulation.ts in both vitest-plugin and tinybench-plugin packages
• Class and function renames: InstrumentedRunner → SimulationRunner, runInstrumentedBench → runSimulationBench, etc.

Reviewed Changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/core/src/index.ts	Updated type definition and logic to map both "instrumentation" and "simulation" to "simulation" mode
packages/core/src/introspection.ts	Updated mode check from "instrumented" to "simulation"
packages/vitest-plugin/src/simulation.ts	Renamed file and all internal functions/classes from "Instrumented" to "Simulation"
packages/vitest-plugin/src/runner.ts	Updated import to use SimulationRunner from simulation module
packages/vitest-plugin/src/index.ts	Updated mode check to compare against "simulation" instead of "instrumented"
packages/vitest-plugin/src/__tests__/instrumented.test.ts	Updated import to use SimulationRunner from simulation module
packages/vitest-plugin/src/__tests__/index.test.ts	Updated expected runner path to reference simulation.ts
packages/vitest-plugin/rollup.config.ts	Updated build configuration to output simulation.mjs instead of instrumented.mjs
packages/tinybench-plugin/src/simulation.ts	Renamed file and all internal functions/classes from "Instrumented" to "Simulation"
packages/tinybench-plugin/src/index.ts	Updated import and mode check to use "simulation"
packages/tinybench-plugin/src/index.unit.test.ts	Added tests for both "instrumentation" (backward compatibility) and "simulation" modes
packages/tinybench-plugin/tests/__snapshots__/index.integ.test.ts.snap	Updated snapshot to reflect "simulation mode" in console output

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[codspeed-hq]

CodSpeed Performance Report

Merging #68 will degrade performances by 55.87%

_{Comparing cod-1441-accept-simulation-as-a-value-instrumentation-which-is-now (635c77c) with main (2e31d9e)¹}

Summary

⚡ 1 improvement
❌ 3 regressions
✅ 126 untouched

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Mode	Benchmark	BASE	HEAD	Change
❌	Simulation	wait 500ms	8.6 ms	12.2 ms	-30.13%
❌	Simulation	short body	132.9 µs	301.3 µs	-55.87%
⚡	WallTime	short body	2 µs	1.7 µs	+13.19%
❌	Simulation	wait 500ms	10.4 ms	12.5 ms	-16.52%

Footnotes

1. No successful run was found on main (635c77c) during the generation of this report, so 2e31d9e was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩