docs(review): Update code review rules

[tab]

• Use CLAUDE.md the single source of truth for architecture, code style, logging, concurrency and security
• Slim .github/CODE_REVIEW.md to review process only: severity, PR hygiene, breaking changes and output format
• Rewrite .github/CODE_REVIEW_PROMPT.md to use CLAUDE.md
• Eliminate cross-file duplication so each rule lives in one place

[Copilot]

Pull request overview

This PR reorganizes the repository’s documentation for AI-assisted development and code review by making CLAUDE.md (+ .claude/skills/*) the canonical source for code rules and reducing .github/CODE_REVIEW.md to the review process and output format.

Changes:

• Slims .github/CODE_REVIEW.md to severity, PR hygiene, breaking changes, and review output format.
• Rewrites .github/CODE_REVIEW_PROMPT.md and .github/copilot-instructions.md to reference CLAUDE.md/skills as authoritative for code rules.
• Adds procedure “skills” docs for verify, test-writing, mock generation, and config reference.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
CLAUDE.md	Refocuses as the canonical code-rules document; trims architectural narrative and centralizes guidelines + workflows.
.github/copilot-instructions.md	Updates Copilot authority chain to prefer CLAUDE.md + skills for code rules and .github/* for review process.
.github/CODE_REVIEW.md	Rewritten to cover only PR review process (severity/hygiene/breaking/output format) and defer code rules to CLAUDE.md/skills.
.github/CODE_REVIEW_PROMPT.md	Updates the multi-pass checklist to cite CLAUDE.md sections and skills for code-rule checks.
.claude/skills/fuku-verify/SKILL.md	Documents the standard verification loop commands (fmt/lint/vet/test/race/e2e).
.claude/skills/fuku-generate-mock/SKILL.md	Documents mockgen conventions (paths, placement, no //go:generate).
.claude/skills/fuku-config/SKILL.md	Adds a fuku.yaml schema reference and semantics notes.
.claude/skills/fuku-add-test/SKILL.md	Documents the table-driven test pattern and related test conventions.

[sentry]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.54%. Comparing base (a63b869) to head (1e6dbdf).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #142   +/-   ##
=======================================
  Coverage   89.54%   89.54%           
=======================================
  Files          66       66           
  Lines        6658     6658           
=======================================
  Hits         5962     5962           
- Misses        537      538    +1     
+ Partials      159      158    -1     

see 1 file with indirect coverage changes

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.