feat(v0.5): expand Tibetan + Theravāda each from 1 → 3 masters (15 total)

Second cross-tradition expansion. v0.4 introduced Milarepa + Ajahn
Chah; this release adds the major foundational figures of each
non-Chinese tradition that were missing.

藏传 (Tibetan): now 3 — Atiśa, Tsongkhapa, Milarepa
南传 (Theravāda): now 3 — Buddhaghosa, Mahasi Sayadaw, Ajahn Chah
汉传 (Chinese): unchanged at 8

New masters
-----------
* prebuilt/atisha/ — Atiśa Dīpaṃkara (982-1054). 噶当派 founder,
  Indo-Tibetan bridge. Sources: Toh 4465 Bodhipathapradīpa + Toh
  3948 self-commentary + 噶当口耳传承 Pha chos / Bu chos. Coverage:
  three scopes, bodhicitta (七因果 + 自他相换 from Suvarṇadvīpa
  Dharmakīrti), 戒律严持, 噶当六论, 依止善知识. HARD-GATE:
  NO_ESOTERIC_INSTRUCTION + NO_ANACHRONISTIC_ATTRIBUTION (don't
  project later Gelug analytical Madhyamaka onto Atiśa's era).

* prebuilt/tsongkhapa/ — Tsongkhapa Lobsang Drakpa (1357-1419).
  Gelug founder, basis of Dalai Lama / Panchen Lama lineages.
  Sources: 宗喀巴全集 gsung 'bum (BDRC searchable) — Lam rim chen
  mo, sNgags rim chen mo, Drang nges legs bshad snying po, 入中论
  善显密意疏, 三主要道. Coverage: 三主要道 (出离心 / 菩提心 / 清净
  见), lamrim, 应成中观, 三聚戒, 闻思修, 五部大论. HARD-GATE:
  NO_ESOTERIC_INSTRUCTION + NO_CROSS_SCHOOL_CONTAMINATION (don't
  blend Dzogchen / Mahāmudrā into Gelug positions) +
  NO_UNVERIFIED_BDRC_W_NUMBERS (descriptive guidance instead of
  fabricated W-IDs; lessons-learned from v0.4 fixup).

* prebuilt/buddhaghosa/ — Buddhaghosa (5th century). 上座部
  commentarial summit. Sources: PTS Vism + four Nikāya aṭṭhakathā
  + Samantapāsādikā (Vinaya) + Atthasālinī (Abhidhamma). Coverage:
  戒定慧三学, 四十种业处, 七清净十六观智, 缘起十二支 (three-life-
  two-causations interpretation), 阿毗达摩 paramattha vs paññatti,
  六义诠释 commentarial method. HARD-GATE:
  NO_MAHAYANA_CONTAMINATION + NO_MAHAVIHARA_PRIMACY_OVERSTATEMENT.

* prebuilt/mahasi-sayadaw/ — Mahāsi Sayādaw U Sobhana (1904-1982).
  Burmese Vipassanā tradition / Mahasi Method. Sources: Manual of
  Insight (Wisdom Publications 2016) + Progress of Insight (BPS
  Sri Lanka Wheel No. 280) + Practical Vipassanā Meditation
  Exercises (Mahasi Sasana Yeiktha) + SC + PTS Vism. Coverage:
  标记法 Noting Method, 腹部起伏 rising-falling primary object,
  七清净十六观智 progress, khaṇika-samādhi & vipassanā-jhāna,
  '初果可证' ethos, MN 10 Satipaṭṭhāna foundation. HARD-GATE:
  NO_FABRICATED_QUOTES + **NO_ATTAINMENT_JUDGMENT** (the strictest
  guardrail in this release — Mahasi's stages-of-insight framework
  is famous for inducing self-attainment delusions; AI is forbidden
  from confirming any individual's observed jhāna stage / fruition).

Each master ships the standard v0.3 progressive-disclosure shape:
SKILL.md (decision tree + HARD-GATE + Quick Reference) + meta.json +
references/{voice,teaching}.md + sources/INDEX.md + ≥1 excerpts file
+ tests/fidelity.jsonl with 12-13 cases each.

ETHICS updates
--------------
* Tier A grows from 9 → 12: Atiśa (>970yr), Tsongkhapa (>600yr),
  Buddhaghosa (>1500yr) all join based on age + open-canon sourcing.
* Tier B 特例 grows from 1 → 2: Mahasi Sayadaw codified under same
  Forest-Sangha-style rationale as Ajahn Chah, with explicit
  NO_ATTAINMENT_JUDGMENT addendum specific to his lineage's risks.
* Sectarian-judgment policy explicit extension: covers Theravāda
  intra-tradition meditation lineages (Mahasi vs Pa-Auk vs Goenka
  vs Thai Forest) — no superiority claims permitted.

compare-masters meta-skill
--------------------------
prebuilt/compare/SKILL.md updated:
* 可用祖师 table now lists all 15 masters by tradition.
* Topic mapping fallback table extended with rows pairing the new
  masters: 中观 (kumarajiva + tsongkhapa), 道次第 (atisha +
  tsongkhapa), 心识 (xuanzang + buddhaghosa + huineng), 戒律
  (xuyun + atisha + buddhaghosa), 禅修方法 (buddhaghosa + mahasi
  + ajahn-chah), 七清净 (buddhaghosa + mahasi), 论师风格 (xuanzang
  + tsongkhapa + buddhaghosa), 三大传统对比 (huineng + tsongkhapa
  + buddhaghosa).
* New cross-tradition guardrails: don't blend traditions (don't
  project Gelug positions onto Atiśa's era; don't put Mahāmudrā
  into Gelug; don't put Tathāgatagarbha into Theravāda).

Surface bumps
-------------
* All 4 plugin manifests + package.json + gemini-extension.json
  bumped 0.4.0 → 0.5.0 with description updated to "15 prebuilt
  masters".
* SKILL.md (project-level) preset list expanded to 8/3/3.
* README.md + README_EN.md: situational guidance table extended
  with cross-tradition rows for the 4 new entries; new master cards
  added with provenance notes; v0.5 release banner appended above
  v0.4 banner.

Validation
----------
* python scripts/validate.py --strict   → ✅ 15 masters pass
* python scripts/validate-fidelity.py   → ✅ all valid
* python scripts/test-fidelity.py --all --dry-run  → ✅
* pytest tests/                          → ✅ 31 passed, 6 skipped

Notes
-----
* fojin_text_ids=[] for new masters — FoJin DB still hasn't imported
  BDRC Tibetan canon nor PTS Vism / SuttaCentral Pali full text;
  RAG falls back to the global corpus and each prompt explicitly
  notes this.
* The two Tibetan masters intentionally use descriptive BDRC
  guidance ("BDRC: 见宗喀巴 gsung 'bum") rather than fabricated
  W-numbers, applying lessons learned from the v0.4 fixup where
  W29193 was mistakenly assigned to two different works in early
  drafts. Toh (Tohoku) numbers are kept where they're well-attested
  in 藏学界 (Toh 4465 for Bodhipathapradīpa).
* CompanionPRs in xr843/fojin (#507 + #508) already synchronized
  the chat-mode subset of these 6 cross-tradition masters; v0.5 of
  this repo brings the Master-skill side to parity.

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

prebuilt/atisha/sources/INDEX.md

@@ -0,0 +1,24 @@
+# 阿底峡尊者 Sources 索引
+
+本目录为离线可用的藏文典籍片段，对应本 master 引用的核心传承文献。
+
+## 收录文件
+
+| 文件 | 来源典籍 | 编号 | 覆盖主题 |
+|---|---|---|---|
+| `bodhipathapradipa-excerpts.md` | 《菩提道灯论》(Bodhipathapradīpa, byang chub lam gyi sgron ma) | [Toh 4465](https://www.84000.co/) | 三士道结构、菩提心、戒律、奢摩他毗钵舍那、密续位置 |
+
+## 引用规范
+
+- 格式：`【《典籍名》§章节】（Toh xxxx / 见 BDRC.io 'a ti sha'）`
+- 示例：`【《菩提道灯论》§菩提心章】（Toh 4465）`
+
+## 说明
+
+- 主要参考：sDe dge bsTan 'gyur Tohoku 4465 (《菩提道灯论》藏文版)
+- 自释《菩提道灯难处释》：Toh 3948
+- 84000 翻译项目（[84000.co](https://84000.co)）已对部分阿底峡论著做权威英译，可对照参阅
+- BDRC.io 收录阿底峡藏文论著及噶当派传承资料，可搜 'a ti sha' 或 'jo bo rje'
+- 汉译参考：任杰译《菩提道灯论》、法尊译《菩提道灯论略释》
+- **密续相关章节本目录刻意不收录**（密法须依止具格上师亲传与灌顶）
+- 增补片段欢迎 PR