docs: reject runs with extra skills outright (addr Codex #25 P2)

A `note` disclosure does not separate a modified-harness run on the board:
leaderboard identity is only model × harness × effort, so a skill-boosted run
would still land in an Agent row it is explicitly not comparable with. Drop the
"disclose in note" escape hatch and make it a flat non-acceptance.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.en.md

@@ -21,7 +21,7 @@ One-shot LLM eval cases by NAGI STUDIO: same prompt, different model x harness x
 - **Model**: the weights and inference engine itself — GPT-5.5, Gemini 3.1 Pro, Claude Fable 5. Reasoning effort is a capability dial of the model itself: the same weights at high vs low effort reason at depths that feel like two different models, so effort belongs to the "model" dimension alongside the weights — judging a model while ignoring its effort isn't fair play. This bench defaults to max and labels the effort of every combination.
 - **Harness**: the product/scaffolding wrapping the model — Codex CLI, Cursor, AntiGravity, the Claude web app. It controls tool calls, system prompts, context management and continuation strategy, and often shapes the outcome as much as the model does.
 - The unit of evaluation here is therefore an **Agent**: the same model (including its effort) under a different harness is a different agent and a separate entry (GPT-5.5 Pro and GPT-5.5 running in Codex CLI at xhigh are two agents from the same model family).
-- **The harness is evaluated as it ships, out of the box**: do not load skills / plugins / MCP servers / custom system prompts beyond what it bundles by default — they shift the output as much as swapping the harness does and break comparability between agents. If you did use any, it is no longer the same agent; disclose it in the `note`.
+- **The harness is evaluated as it ships, out of the box**: do not load skills / plugins / MCP servers / custom system prompts beyond what it bundles by default — they shift the output as much as swapping the harness does and break comparability between agents. Such runs are **not accepted** (the leaderboard identity is just model × harness × effort, so a `note` does not give them a separate identity).
 
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