Add terminal load perf summary output

[almogdepaz]

Summary

• print a readable aggregate summary before the perf harness JSON block
• add WOLFPACK_PERF_HELP=1 env help for supported perf knobs
• keep existing JSON report shape and measurement flow unchanged

Verification

• red: new terminal-load perf unit contracts failed on missing formatPerfRunsSummary
• bun test tests/unit/terminal-load-perf.test.ts — 10 passed
• bun run typecheck
• WOLFPACK_PERF_HELP=1 bun run scripts/terminal-load-perf.ts
• page-only smoke: WOLFPACK_PERF_RUNS=2 WOLFPACK_PERF_ONLY_PAGE_LOAD=1 ... bun run scripts/terminal-load-perf.ts
  • aggregate summary printed
  • JSON parsed
  • summary.runs = 2
  • console errors 0
• small full smoke: WOLFPACK_PERF_GRID_CELLS=2 WOLFPACK_PERF_RUNS=1 ... bun run scripts/terminal-load-perf.ts
  • single/grid aggregate lines printed
  • JSON parsed
  • grid prewarm hits 2/2
  • remaining perf-* sessions 0
• git diff --check
• GIT_CONFIG_COUNT=1 GIT_CONFIG_KEY_0=commit.gpgsign GIT_CONFIG_VALUE_0=false bun test — 1820 passed

Note: commit signing is disabled for the full suite because this local shell otherwise triggers 1Password signing inside child git repos.

[almogdepaz]

subagent review: clean. focused on terminal-load perf changes: aggregate summary is additive before json:, WOLFPACK_PERF_HELP=1 exits before broker/server/dev-dir side effects, JSON report shape remains compatible, repeated-run loop/cleanup semantics unchanged. also ran focused unit test + typecheck.