docs: regenerate this repo's instruction files through the install path

Ran skills.inject_instruction_files against this checkout rather than
hand-editing, so the upgrade path from the previous commit is proven on real
files that have carried the stale wording since before the guardrails existed.

CLAUDE.md, AGENTS.md and GEMINI.md each held the previous generated block with
a markdown formatter's normalized table separator; all three upgraded in place
and every byte outside the block is unchanged.
.github/code-review-graph.instruction.md is a superseded path, so the same run
removed it, taking with it a Copilot variant that told agents to prefer the
graph over #tool:search.
.github/copilot-instructions.md is not owned by the platform table, so it went
through skills._inject_instructions directly with the same marker and section.

The install path also writes .cursorrules, .windsurfrules, CODEBUDDY.md,
QODER.md and the .kiro and .github/instructions files. This repo does not track
those, so they were removed again rather than committed.

Refs #314

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012fHfGDiZedoxjpKzanHri3