docs: add data source flow guide and localize handoff READMEs

- Add docs/DATA_SOURCE_FLOW.md: end-to-end source -> NotebookLM ->
  storage -> App flow, source list with publish frequency, institution
  intro status, ingestion artifact structure, and known cadence gaps
- Link the new doc from README and PROJECT_OVERVIEW indexes
- Localize top-level and subproject READMEs to Chinese for handoff
  (pre-existing working-tree changes)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -1,78 +1,79 @@
-# Yanting / report-notebooklm
+# 研听 / report-notebooklm
 
-`研听` is a Phase 1 app and backend for turning global institutional research reports into structured Chinese reading and listening experiences.
+`研听` 是一个第一阶段（Phase 1）的应用和后端，用来把全球机构研报转化成结构化的中文阅读与收听体验。
 
-This repository is prepared as a single Gitea handoff repository for product and engineering teams.
+这个仓库被整理成单个 Gitea 交接仓库，供产品和工程团队接手使用。
 
-## What Is In This Repository
+## 仓库里有什么
 
-| Area | Path | Description |
+| 区域 | 路径 | 说明 |
 |---|---|---|
-| Backend API | `report-notebooklm-api/` | FastAPI service, MySQL models, Alembic migration, seed importer, public read API. |
-| Flutter App | `report-notebooklm-app/` | Flutter client with five main tabs, report detail modules, Android/web scaffolds. |
-| Repo docs | `docs/` | Project-level overview, decisions, development history, and handoff guidance. |
-| Backend docs | `report-notebooklm-api/docs/` | API/data/content-pipeline/runbook details. |
-| App docs | `report-notebooklm-app/docs/` | App runbook, project map, and API consumption notes. |
+| 后端 API | `report-notebooklm-api/` | FastAPI 服务、MySQL 模型、Alembic 迁移、种子数据导入、对外只读 API。 |
+| Flutter 应用 | `report-notebooklm-app/` | Flutter 客户端，包含五个主标签页、研报详情模块、Android/Web 脚手架。 |
+| 仓库文档 | `docs/` | 项目级概览、决策记录、开发历程和交接指南。 |
+| 后端文档 | `report-notebooklm-api/docs/` | API、数据、内容流水线、运维手册的细节。 |
+| 应用文档 | `report-notebooklm-app/docs/` | 应用运维手册、项目地图、API 调用说明。 |
 
-## Product Snapshot
+## 产品速览
 
-`研听` helps Chinese users understand global institutional research reports across macro, precious metals, commodities, energy, central banks, and cross-asset topics.
+`研听` 帮助中文用户读懂全球机构研报，覆盖宏观、贵金属、大宗商品、能源、央行、跨资产等主题。
 
-Phase 1 focuses on:
+第一阶段聚焦在：
 
-- 推荐: curated/latest report interpretations.
-- 研报: report list and basic filtering.
-- 机构: institution list and institution detail.
-- 听单: reports that have audio.
-- 我的: guest/login state and shallow personal-state entries.
+- 推荐：精选 / 最新的研报解读。
+- 研报：研报列表和基础筛选。
+- 机构：机构列表和机构详情。
+- 听单：带音频的研报。
+- 我的：游客 / 登录状态，以及浅层的个人状态入口。
 
-Phase 1 explicitly does not include comments, UGC, paid unlocks, membership, ads, trading signals, investment advice, or report-interpretation downloads.
+第一阶段明确**不包含**：评论、UGC、付费解锁、会员、广告、交易信号、投资建议、研报解读下载。
 
-## Read First
+## 先读这些
 
-For human readers:
+给人类读者：
 
 1. `docs/PROJECT_OVERVIEW.md`
 2. `docs/DECISIONS.md`
-3. `docs/DEVELOPMENT_HISTORY.md`
-4. `report-notebooklm-api/docs/HANDOFF.md`
-5. `report-notebooklm-app/docs/HANDOFF.md`
+3. `docs/DATA_SOURCE_FLOW.md`
+4. `docs/DEVELOPMENT_HISTORY.md`
+5. `report-notebooklm-api/docs/HANDOFF.md`
+6. `report-notebooklm-app/docs/HANDOFF.md`
 
-For agents:
+给 AI agent：
 
 1. `AGENTS.md`
 2. `docs/DECISIONS.md`
-3. Target subsystem README and runbook.
+3. 对应子系统的 README 和运维手册。
 
-## Current Implementation Status
+## 当前实现状态
 
-Backend implemented:
+后端已实现：
 
-- FastAPI app under `/api/report-notebooklm/v1`.
-- SQLAlchemy model layer for Phase 1 tables.
-- Alembic initial migration.
-- Seed import script.
-- Public read endpoints for health, feed, reports, report modules, institutions, and listen list.
-- Tests for seed and public API behavior.
+- 挂在 `/api/report-notebooklm/v1` 下的 FastAPI 应用。
+- 第一阶段数据表的 SQLAlchemy 模型层。
+- Alembic 初始迁移。
+- 种子数据导入脚本。
+- 健康检查、信息流、研报、研报模块、机构、听单的对外只读接口。
+- 针对种子数据和对外 API 行为的测试。
 
-App implemented:
+应用已实现：
 
-- Five bottom tabs: 推荐, 研报, 机构, 听单, 我的.
-- API-backed list/detail views using `RNB_API_BASE`.
-- Report detail module renderer registry.
-- Local placeholders for login, favorites, outbound confirmation, and playback progress.
-- Android and web build scaffolds.
+- 五个底部标签页：推荐、研报、机构、听单、我的。
+- 基于 `RNB_API_BASE` 的列表 / 详情视图。
+- 研报详情的模块渲染器注册表。
+- 登录、收藏、外链跳转确认、播放进度的本地占位实现。
+- Android 和 Web 构建脚手架。
 
-Not production-ready yet:
+尚未达到生产可用：
 
-- Auth and personal state.
-- Real audio stream signing.
-- Outbound event writing.
-- Internal content management API.
-- Production object storage and cache invalidation.
-- Production API domain, release signing, final app icon, and store metadata.
+- 鉴权和个人状态。
+- 真实的音频流签名。
+- 外链事件写入。
+- 内部内容管理 API。
+- 生产环境对象存储和缓存失效。
+- 生产 API 域名、发布签名、最终应用图标、应用商店元信息。
 
-## Backend Quick Start
+## 后端快速上手
 
 ```bash
 cd report-notebooklm-api
@@ -80,13 +81,13 @@ python -m venv .venv
 source .venv/bin/activate
 pip install -e ".[dev]"
 cp .env.example .env
-# edit .env for your MySQL and Redis
+# 按你的 MySQL 和 Redis 编辑 .env
 alembic upgrade head
 python scripts/import_seed_content.py
 uvicorn app.main:app --reload --host <bind-host> --port <port>
 ```
 
-Smoke checks:
+冒烟检查：
 
 ```bash
 API_BASE_URL=http://<api-host>:<port>/api/report-notebooklm/v1
@@ -95,7 +96,7 @@ curl "$API_BASE_URL/feed/recommended"
 curl "$API_BASE_URL/reports/rep_ssga_gold"
 ```
 
-## App Quick Start
+## 应用快速上手
 
 ```bash
 cd report-notebooklm-app
@@ -104,15 +105,15 @@ flutter test
 flutter run -d chrome --dart-define=RNB_API_BASE=<api-base-url>
 ```
 
-Android emulator:
+Android 模拟器：
 
 ```bash
 flutter run -d <emulator-id> --dart-define=RNB_API_BASE=<emulator-api-base-url>
 ```
 
-## Verification
+## 验证
 
-Backend:
+后端：
 
 ```bash
 cd report-notebooklm-api
@@ -120,7 +121,7 @@ source .venv/bin/activate
 pytest -q
 ```
 
-App:
+应用：
 
 ```bash
 cd report-notebooklm-app
@@ -130,10 +131,10 @@ flutter build web --dart-define=RNB_API_BASE=<api-base-url>
 flutter build apk --debug --dart-define=RNB_API_BASE=<emulator-api-base-url>
 ```
 
-## Documentation Boundary
+## 文档边界
 
-This repository contains a code handoff snapshot. It does not replace the product source of truth.
+这个仓库是一份代码交接快照，不能替代产品的唯一真源（SSOT）。
 
-Product SSOT: mall-docs report-notebooklm docs, snapshot date: 2026-06-03.
+产品 SSOT：mall-docs 里的 report-notebooklm 文档，快照日期：2026-06-03。
 
-Local-only notes, private paths, raw session pointers, and personal agent workflow belong in ignored `docs.jimme.local/` and `AGENTS.local.md`.
+仅限本机的笔记、私有路径、原始会话指针、个人 agent 工作流，都应放在被忽略的 `docs.jimme.local/` 和 `AGENTS.local.md` 里。