feat(api): define Feed/Chatter API protocol endpoints

[Copilot]

Feed/Chatter data models and UI props landed in PR#732 but lack corresponding API endpoint contracts. This adds the HTTP interface specification for Feed CRUD, Reactions, and Subscription.

src/api/feed-api.zod.ts

8 endpoints following existing contract patterns (BaseResponseSchema.extend(), Zod-first, .describe() annotations):

• Feed CRUD — GET /feed (cursor pagination + type filter), POST /feed, PUT /feed/:feedId, DELETE /feed/:feedId
• Reactions — POST /feed/:feedId/reactions, DELETE /feed/:feedId/reactions/:emoji
• Subscription — POST /subscribe, DELETE /subscribe

All under base path /api/data/:object/:recordId/.

Reuses existing data-layer schemas (FeedItemSchema, ReactionSchema, MentionSchema, RecordSubscriptionSchema) — no duplication.

Includes FeedApiErrorCode enum and FeedApiContracts registry for SDK/doc generation:

import { FeedApiContracts, GetFeedRequestSchema } from '@objectstack/spec';

// Contract registry maps method + path + input/output for all 8 endpoints
FeedApiContracts.listFeed.method   // 'GET'
FeedApiContracts.listFeed.path     // '/api/data/:object/:recordId/feed'
FeedApiContracts.addReaction.input // AddReactionRequestSchema

// Request validation with defaults
const req = GetFeedRequestSchema.parse({
  object: 'account',
  recordId: 'rec_123',
}); // → { type: 'all', limit: 20, cursor: undefined, ... }

Other changes

• src/api/index.ts — export feed-api.zod
• ROADMAP.md — API Protocol line updated
• 45 tests covering all schemas, defaults, validation, error codes, and contract registry

Original prompt

---

This section details on the original issue you should resolve

<issue_title>定义 Feed/Chatter 协议 API 端点（Feed CRUD、Reactions、Subscription）</issue_title>
<issue_description>### 背景

[Feed/Chatter 协议相关数据模型、UI props 已完成](#731 & PR#732)。目前暂无配套的 API 协议，无法规范服务端和前端协作的接口约定。

目标

• 定义统一的 Feed/Chatter 接口端点，包括 Feed CRUD、Reactions、Subscription
• 明确请求/响应参数 schema，便于前后端约束和 mock
• 对标 Airtable/Salesforce/Notion Timeline

推荐端点

• GET /api/data/{object}/{recordId}/feed?type=all&limit=20&cursor=xxx — 拉取某条记录的活动时间线（混合评论、字段变更、task 等，支持翻页和类型筛选）

• POST /api/data/{object}/{recordId}/feed { type: 'comment', body: '...'} — 新增评论/任务等 Feed 项

• PUT /api/data/{object}/{recordId}/feed/{feedId} { body: '...'} — 编辑评论等

• DELETE /api/data/{object}/{recordId}/feed/{feedId} — 删除 Feed 项（如评论）

• POST /api/data/{object}/{recordId}/feed/{feedId}/reactions { emoji: '👍'} — 增加 emoji reaction

• DELETE /api/data/{object}/{recordId}/feed/{feedId}/reactions/{emoji} — 移除 reaction

• POST /api/data/{object}/{recordId}/subscribe { events: ['comment'...'field_change'...'all'], channels: ['in_app'...'email']}

• DELETE /api/data/{object}/{recordId}/subscribe

期望

• 每个端点均应有详细的请求/响应参数 JSON schema（建议 Zod/TSType/JSON Schema）
• 补充接口错误说明，例如权限不足、非法操作
• 示例：如何通过 API 拉取包含评论、字段变更、回复和 reaction 的 unified feed 时间线

参考

• 已合并 PR#732（协议/模型实现）
• [Airtable / Salesforce Chatter / Notion 评论Feed]
• [协议增强：实现 Airtable 风格的 Comments & Activity Timeline（Feed/Chatter 协议标准） #731]

---

test

---

建议实现：可新建 src/api/feed-api.zod.ts 或在现有 API contract 体系扩展

完成后请运行 test，并更新 ROADMAP</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes 定义 Feed/Chatter 协议 API 端点（Feed CRUD、Reactions、Subscription） #733

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Project	Deployment	Actions	Updated (UTC)
objectstack-play	Ready	Preview, Comment	Feb 19, 2026 8:31am
spec	Ready	Preview, Comment	Feb 19, 2026 8:31am

[Copilot]

Pull request overview

This PR completes the Feed/Chatter API protocol by defining 8 HTTP endpoint specifications to complement the data models introduced in PR#732. The API follows Airtable/Salesforce Chatter patterns for unified activity timelines.

Changes:

• Adds complete Feed/Chatter API endpoint definitions with Zod-first schemas, cursor pagination, and comprehensive error codes
• Introduces enhanced contract registry pattern that includes HTTP method and path alongside input/output schemas for improved SDK/documentation generation
• Updates ROADMAP.md to reflect Feed API completion

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
packages/spec/src/api/feed-api.zod.ts	Defines 8 Feed API endpoints (CRUD, Reactions, Subscription) with complete request/response schemas, path parameters, error codes, and enhanced contract registry following existing patterns
packages/spec/src/api/feed-api.test.ts	Comprehensive test suite with 45 tests covering all schemas, validation rules, defaults, pagination, and edge cases
packages/spec/src/api/index.ts	Exports feed-api module following existing export conventions
ROADMAP.md	Updates API Protocol section to document Feed API (Feed CRUD, Reactions, Subscription) completion