feat: expand to Tibetan + Theravada — 10 masters across 三大传统 (v0.4)

Adds the project's first non-Chinese masters, taking the scope from
"Chinese Buddhist" to "Buddhist" and matching the project name's
broader implication.

New masters
-----------
• prebuilt/milarepa — Tibetan Kagyu yogi (1052–1135). Sources:
  The Hundred Thousand Songs of Milarepa (mGur 'bum, BDRC W1KG14334)
  and The Life of Milarepa (rNam thar, BDRC W22272). Coverage:
  Mahāmudrā view, Naro Chodruk (name-level only — no esoteric steps),
  retreat & austerity, guru yoga, karma & purification.

• prebuilt/ajahn-chah — Thai Forest Tradition founder of Wat Pah Pong
  (1918–1992). Sources: Pali Canon (SuttaCentral SC IDs) plus
  authorized English collections Food for the Heart, A Still Forest
  Pool, Living Dhamma. Coverage: sati & satipaṭṭhāna, ānāpānasati,
  three characteristics, letting go, sīla-samādhi-paññā, middle way.

HARD-GATE additions
-------------------
• no_esoteric_instruction — Tibetan tantric practice steps (tummo,
  generation/completion stages, empowerment-required visualizations
  and mantras) are never disclosed; queries are redirected to
  qualified teachers. Boundary registered in
  scripts/validate-fidelity.py.

• No fabricated quotes for Theravāda discourses — Ajahn Chah quotes
  must trace to authorized publications; no synthesized "Ajahn Chah
  said" dialogue.

Citation system
---------------
BDRC:Wxxxxx (Tibetan canon) and SuttaCentral SC IDs are now
first-class alongside CBETA Txxnxxxx in frontmatter sources lists.
validate.py already accepts non-cbeta sources via the existing
title-or-cbeta_id check, no schema change required.

Cross-tradition compare-masters mappings
----------------------------------------
prebuilt/compare/SKILL.md gets new fallback rows for: 苦行/闭关
(xuyun + milarepa), 正念/觉知 (huineng + ajahn-chah + xuyun),
出离心/无常 (yinguang + milarepa + ajahn-chah), 三大传统对比
(huineng + milarepa + ajahn-chah), and adds milarepa to 般若/空性,
ajahn-chah to 戒律/行持.

Surface updates
---------------
• Description across package.json, .claude-plugin/{plugin,marketplace}.json,
  .cursor-plugin/plugin.json: "Chinese Buddhist" → "Buddhist",
  "8 prebuilt masters" → "10 prebuilt masters across 汉传/藏传/南传".
• README.md + README_EN.md: cross-tradition rows in the situational
  guidance table; new master cards for Milarepa and Ajahn Chah with
  appropriate provenance notes; v0.4 release banner replaces v0.3.
• SKILL.md preset list reorganized by tradition.
• CHANGELOG.md gets a [0.4.0] section.
• package.json keywords add tibetan-buddhism, theravada, bdrc,
  suttacentral.

Validation
----------
• python scripts/validate.py --strict → ✅ 11 masters pass
• python scripts/validate-fidelity.py → ✅ 11 masters validated
  (12 + 13 fidelity cases for the two new masters)
• python scripts/test-fidelity.py --all --dry-run → ✅
• pytest tests/ → ✅ 31 passed, 6 skipped

The progressive-disclosure shape of v0.3 is preserved exactly, so
the fidelity-smoke CI cost cap is unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

prebuilt/ajahn-chah/meta.json

@@ -0,0 +1,100 @@
+{
+  "name": "阿姜查",
+  "name_thai": "อาจารย์ชา",
+  "name_pali": "Ajahn Chah Subhaddo",
+  "slug": "ajahn-chah",
+  "tradition": "南传",
+  "school": "上座部（泰国森林禅林派 / 巴蓬寺传承）",
+  "era": "1918-1992",
+  "languages": [
+    "th",
+    "en",
+    "zh"
+  ],
+  "fojin_entity_id": null,
+  "sources": [
+    {
+      "type": "pali_canon",
+      "id": "SuttaCentral",
+      "title": "巴利三藏（Sutta Piṭaka）"
+    },
+    {
+      "type": "compiled_teaching",
+      "id": "AjahnChah:FoodForTheHeart",
+      "title": "Food for the Heart（《心灵的资粮》）"
+    },
+    {
+      "type": "compiled_teaching",
+      "id": "AjahnChah:StillForestPool",
+      "title": "A Still Forest Pool（《静止的流水》）"
+    },
+    {
+      "type": "compiled_teaching",
+      "id": "AjahnChah:LivingDhamma",
+      "title": "Living Dhamma（《活生生的法》）"
+    }
+  ],
+  "version": "1.0.0",
+  "created_at": "2026-05-02",
+  "updated_at": "2026-05-02",
+  "disclaimer": "本内容依据上座部巴利经典与阿姜查公开开示集生成，仅供参考学习。如需正式修行指导，请亲近具格戒师与禅师。",
+  "search_scope": {
+    "primary_source_ids": [
+      "SuttaCentral",
+      "AjahnChah:FoodForTheHeart",
+      "AjahnChah:StillForestPool"
+    ],
+    "traditions": [
+      "上座部",
+      "森林禅林派",
+      "Theravada",
+      "Thai Forest"
+    ],
+    "dictionary_sources": [
+      "pts_dictionary",
+      "suttacentral_glossary"
+    ],
+    "keywords": [
+      "正念",
+      "sati",
+      "觉知",
+      "awareness",
+      "放下",
+      "let go",
+      "戒定慧",
+      "sila samadhi panna",
+      "无常",
+      "anicca",
+      "苦",
+      "dukkha",
+      "无我",
+      "anatta",
+      "三法印",
+      "tilakkhana",
+      "四念处",
+      "satipatthana",
+      "出入息念",
+      "anapanasati",
+      "禅那",
+      "jhana",
+      "vipassana",
+      "毗婆舍那",
+      "习气",
+      "kilesa",
+      "心的训练",
+      "training the mind",
+      "森林禅林",
+      "巴蓬寺",
+      "Wat Pah Pong",
+      "杜多行",
+      "dhutanga",
+      "sangha",
+      "vinaya",
+      "戒律",
+      "中道",
+      "majjhima patipada",
+      "如实观",
+      "yathabhutam"
+    ]
+  }
+}