fix(i18n): revert Diligence regression + complete Agent Skills brand-policy (#221)

An independent adversarial cross-validation (Codex, different model lineage)
found two real defects in the recent i18n PRs; both reproduced locally.

1. Diligence regression (from #219). The AI Fluency "4D" competency Diligence is
   defined in-file as "informed responsibility for outputs — verify facts, check
   biases, ensure accuracy" (due diligence), but #219 changed zh-CN/zh-TW to
   勤奋/勤勉 ("industrious/hardworking"), which mismatches that meaning. The
   pre-#219 审核/審核 ("review/verify") was actually closer. Revert all 14
   occurrences (keeping the correct Delegation 委托/委派 fix). The optimal
   rendering (e.g. 审慎/尽责) is flagged for the #202 native review.

2. Agent Skills brand-policy was applied inconsistently in #219 — "Introduction
   to agent skills" still translated the product name in 8 locales. Restore the
   English product name "Agent Skills": es/fr/it/ja/pt-BR/vi/zh-TW + de hyphen
   (Agent-Skills → Agent Skills). ru is left as-is: its product term is the one
   genuinely contested cell (official RU docs translate Skills → "Навыки агента"
   while the dev community keeps English) — deferred to #202.

Value-only edits (key-parity holds). 9 gates green · 553 unit · e2e 20/20.

Two further Codex findings are design/minor and handled separately: the phonetic
brand-transliteration restores (克洛德/クロード/Клод) corrupt real person names
(Claude Monet/Debussy) — a real but low-frequency tradeoff on Academy pages,
pending an owner decision on a name-particle guard; and an NFD/combining-mark
edge where a precomposed protected form misses decomposed input (minor).

Author: heznpc

claude-plugin/skills/academy-terms/data/terms.de.json

@@ -75,7 +75,7 @@
     "This course empowers academic faculty, instructional designers, and others to teach and assess AI Fluency in instructor-led settings.": "Dieser Kurs befähigt akademische Lehrende, Instructional Designer und andere, KI-Kompetenz in von Instruktoren geleiteten Umgebungen zu unterrichten und zu bewerten.",
     "AI Fluency for nonprofits": "KI-Kompetenz für gemeinnützige Organisationen",
     "This course empowers nonprofit professionals to develop AI fluency in order to increase organizational impact and efficiency while staying true to their mission and values.": "Dieser Kurs befähigt Fachleute von gemeinnützigen Organisationen, KI-Kompetenz zu entwickeln, um die organisatorische Wirkung und Effizienz zu erhöhen, während sie ihrer Mission und ihren Werten treu bleiben.",
-    "Introduction to agent skills": "Einführung in Agent-Skills",
+    "Introduction to agent skills": "Einführung in Agent Skills",
     "Learn how to build, configure, and share Skills in Claude Code — reusable markdown instructions that Claude automatically applies to the right tasks at the right time. This course takes you from creating your first Skill to distributing them across teams and troubleshooting common issues.": "Erfahren Sie, wie Sie Skills in Claude Code erstellen, konfigurieren und teilen – wiederverwendbare Markdown-Anweisungen, die Claude automatisch zur richtigen Zeit auf die richtigen Aufgaben anwendet. Dieser Kurs führt Sie von der Erstellung Ihres ersten Skills über die Verteilung in Teams bis zur Behebung häufiger Probleme.",
     "Introduction to Claude Cowork": "Einführung in Claude Cowork",
     "This hands-on course covers the Cowork task loop, plugins and skills, file and research workflows, and how to steer multi-step work responsibly — so you're productive in your first week.": "Dieser praktische Kurs behandelt die Cowork-Aufgabenschleife, Plugins und Skills, Datei- und Recherche-Workflows sowie die verantwortungsvolle Steuerung mehrstufiger Arbeit.",

claude-plugin/skills/academy-terms/data/terms.es.json

@@ -75,7 +75,7 @@
     "This course empowers academic faculty, instructional designers, and others to teach and assess AI Fluency in instructor-led settings.": "Este curso capacita a profesores académicos, diseñadores instruccionales y otros para enseñar y evaluar la Fluidez en IA en entornos dirigidos por instructores.",
     "AI Fluency for nonprofits": "Fluidez en IA para organizaciones sin ánimo de lucro",
     "This course empowers nonprofit professionals to develop AI fluency in order to increase organizational impact and efficiency while staying true to their mission and values.": "Este curso capacita a profesionales de organizaciones sin ánimo de lucro para desarrollar fluidez en IA con el fin de aumentar el impacto y la eficiencia organizacional mientras se mantienen fieles a su misión y valores.",
-    "Introduction to agent skills": "Introducción a las habilidades de agente",
+    "Introduction to agent skills": "Introducción a Agent Skills",
     "Learn how to build, configure, and share Skills in Claude Code — reusable markdown instructions that Claude automatically applies to the right tasks at the right time. This course takes you from creating your first Skill to distributing them across teams and troubleshooting common issues.": "Aprende cómo construir, configurar y compartir Habilidades en Claude Code, instrucciones markdown reutilizables que Claude aplica automáticamente a las tareas correctas en el momento correcto. Este curso te lleva desde crear tu primera Habilidad hasta distribuirlas entre equipos y resolver problemas comunes.",
     "Introduction to Claude Cowork": "Introducción a Claude Cowork",
     "This hands-on course covers the Cowork task loop, plugins and skills, file and research workflows, and how to steer multi-step work responsibly — so you're productive in your first week.": "Este curso práctico cubre el bucle de tareas de Cowork, plugins y habilidades, flujos de trabajo de archivos e investigación, y cómo dirigir el trabajo de múltiples pasos de manera responsable.",

claude-plugin/skills/academy-terms/data/terms.fr.json

@@ -75,7 +75,7 @@
     "This course empowers academic faculty, instructional designers, and others to teach and assess AI Fluency in instructor-led settings.": "Ce cours permet aux professeurs universitaires, aux concepteurs pédagogiques et à d'autres d'enseigner et d'évaluer la Maîtrise de l'IA dans des environnements dirigés par un instructeur.",
     "AI Fluency for nonprofits": "Maîtrise de l'IA pour les organisations à but non lucratif",
     "This course empowers nonprofit professionals to develop AI fluency in order to increase organizational impact and efficiency while staying true to their mission and values.": "Ce cours permet aux professionnels des organisations à but non lucratif de développer une maîtrise de l'IA afin d'augmenter l'impact et l'efficacité organisationnels tout en restant fidèles à leur mission et leurs valeurs.",
-    "Introduction to agent skills": "Introduction aux compétences d'agent",
+    "Introduction to agent skills": "Introduction à Agent Skills",
     "Learn how to build, configure, and share Skills in Claude Code — reusable markdown instructions that Claude automatically applies to the right tasks at the right time. This course takes you from creating your first Skill to distributing them across teams and troubleshooting common issues.": "Apprenez à créer, configurer et partager des Compétences dans Claude Code (des instructions markdown réutilisables que Claude applique automatiquement aux bonnes tâches au bon moment). Ce cours vous accompagne de la création de votre première Compétence jusqu'à leur distribution au sein des équipes et à la résolution des problèmes courants.",
     "Introduction to Claude Cowork": "Introduction à Claude Cowork",
     "This hands-on course covers the Cowork task loop, plugins and skills, file and research workflows, and how to steer multi-step work responsibly — so you're productive in your first week.": "Ce cours pratique couvre la boucle de tâches Cowork, les plugins et compétences, les flux de travail de fichiers et de recherche, et comment diriger le travail en plusieurs étapes de manière responsable.",

claude-plugin/skills/academy-terms/data/terms.it.json

@@ -73,7 +73,7 @@
     "This course empowers academic faculty, instructional designers, and others to teach and assess AI Fluency in instructor-led settings.": "Questo corso consente a docenti accademici, progettisti didattici e altri soggetti di insegnare e valutare la fluidità dell'intelligenza artificiale in contesti guidati da istruttori.",
     "AI Fluency for nonprofits": "Conoscenza dell'intelligenza artificiale per le organizzazioni non profit",
     "This course empowers nonprofit professionals to develop AI fluency in order to increase organizational impact and efficiency while staying true to their mission and values.": "Questo corso consente ai professionisti no-profit di sviluppare la padronanza dell'intelligenza artificiale al fine di aumentare l'impatto e l'efficienza organizzativa rimanendo fedeli alla propria missione e ai propri valori.",
-    "Introduction to agent skills": "Introduzione alle skills dell'agente",
+    "Introduction to agent skills": "Introduzione ad Agent Skills",
     "Learn how to build, configure, and share Skills in Claude Code — reusable markdown instructions that Claude automatically applies to the right tasks at the right time. This course takes you from creating your first Skill to distributing them across teams and troubleshooting common issues.": "Scopri come creare, configurare e condividere le skills in Claude Code: istruzioni di markdown riutilizzabili che Claude applica automaticamente alle attività giuste al momento giusto. Questo corso ti porta dalla creazione delle tue prime skills alla loro distribuzione tra i team e alla risoluzione dei problemi comuni.",
     "Introduction to Claude Cowork": "Introduzione a Claude Cowork",
     "This hands-on course covers the Cowork task loop, plugins and skills, file and research workflows, and how to steer multi-step work responsibly — so you're productive in your first week.": "Questo corso pratico copre il ciclo di attività di Cowork, i plug-in e le skills, i flussi di lavoro di file e ricerca e come gestire il lavoro in più fasi in modo responsabile, così sarai produttivo già nella prima settimana.",

claude-plugin/skills/academy-terms/data/terms.ja.json

@@ -84,7 +84,7 @@
     "This course empowers academic faculty, instructional designers, and others to teach and assess AI Fluency in instructor-led settings.": "このコースは、学術的教職員、インストラクショナルデザイナー、および他の人々がインストラクター主導の設定でAI流暢性を教え、評価できるようにします。",
     "AI Fluency for nonprofits": "非営利団体向けAI流暢性",
     "This course empowers nonprofit professionals to develop AI fluency in order to increase organizational impact and efficiency while staying true to their mission and values.": "このコースは、非営利団体の専門家がAI流暢性を開発し、ミッションと価値を守りながら組織の影響力と効率性を高めることができるようにします。",
-    "Introduction to agent skills": "エージェントスキルの紹介",
+    "Introduction to agent skills": "Agent Skills の紹介",
     "Learn how to build, configure, and share Skills in Claude Code — reusable markdown instructions that Claude automatically applies to the right tasks at the right time. This course takes you from creating your first Skill to distributing them across teams and troubleshooting common issues.": "Claude Codeでスキルをビルド、構成、共有する方法を学習します。Claudeが正しい時間に正しいタスクに自動的に適用する再利用可能なマークダウン指示です。このコースでは、最初のスキルの作成から、チーム全体への配布、一般的な問題のトラブルシューティングまでをカバーしています。",
     "Introduction to Claude Cowork": "Claude Cowork入門",
     "This hands-on course covers the Cowork task loop, plugins and skills, file and research workflows, and how to steer multi-step work responsibly — so you're productive in your first week.": "このハンズオンコースでは、Coworkタスクループ、プラグインとスキル、ファイルとリサーチのワークフロー、そしてマルチステップの作業を責任を持って進める方法をカバーします。",

claude-plugin/skills/academy-terms/data/terms.vi.json

@@ -72,7 +72,7 @@
     "This course empowers academic faculty, instructional designers, and others to teach and assess AI Fluency in instructor-led settings.": "Khóa học này trao quyền cho giảng viên đại học, nhà thiết kế giảng dạy và những người khác để giảng dạy và đánh giá Thành thạo AI trong các môi trường do giảng viên hướng dẫn.",
     "AI Fluency for nonprofits": "Thành thạo AI cho tổ chức phi lợi nhuận",
     "This course empowers nonprofit professionals to develop AI fluency in order to increase organizational impact and efficiency while staying true to their mission and values.": "Khóa học này trao quyền cho các chuyên gia tổ chức phi lợi nhuận phát triển sự thành thạo AI nhằm tăng tác động và hiệu quả tổ chức trong khi vẫn trung thành với sứ mệnh và giá trị của họ.",
-    "Introduction to agent skills": "Giới thiệu về kỹ năng agent",
+    "Introduction to agent skills": "Giới thiệu về Agent Skills",
     "Learn how to build, configure, and share Skills in Claude Code — reusable markdown instructions that Claude automatically applies to the right tasks at the right time. This course takes you from creating your first Skill to distributing them across teams and troubleshooting common issues.": "Học cách xây dựng, cấu hình và chia sẻ Skills trong Claude Code — các hướng dẫn markdown có thể tái sử dụng mà Claude tự động áp dụng vào đúng tác vụ vào đúng thời điểm. Khóa học này đưa bạn từ việc tạo Skill đầu tiên đến phân phối chúng trong các nhóm và xử lý sự cố thường gặp.",
     "Introduction to Claude Cowork": "Giới thiệu về Claude Cowork",
     "This hands-on course covers the Cowork task loop, plugins and skills, file and research workflows, and how to steer multi-step work responsibly — so you're productive in your first week.": "Khóa học thực hành này bao gồm vòng lặp tác vụ Cowork, plugin và skill, quy trình làm việc với tệp và nghiên cứu, và cách điều hướng công việc nhiều bước một cách có trách nhiệm.",