feat: complete OAuth flow, preferences API, /signal help, HandleAppMe…

[LSUDOKO]

…ntion

• Add /oauth/start endpoint that redirects to Slack OAuth with proper scopes
• Fix OAuth redirect_uri to use frontend callback page
• Capture authed_user.id in OAuth response, pass slack_user_id + team_id to frontend
• Add preferences-by-slack API endpoints (GET/PUT) for frontend
• Add user-by-slack API endpoints (GET/PUT) for neurotype management
• Wire App Home preferences form to real API calls with loading state
• Fix Add to Slack buttons on landing page to use /oauth/start
• OAuth callback page now redirects browser to API for token exchange
• Implement /signal slash command with help block
• Implement HandleAppMention with help message in DM
• Fix /metrics endpoint with promhttp.Handler()

What

How to Test

Checklist

• make lint passes
• make test passes
• Feature tested in Slack sandbox
• Demo video updated (if UX changed)
• Docs updated (if API changed)

Summary by CodeRabbit

• New Features

  • Added Slack installation and OAuth flow with automatic redirect back to the app.
  • App Home now loads and saves preferences using the connected Slack account and workspace.
  • Added support for updating neurotype and preferences, including sensible defaults for new users.
  • Added Slack-based user and preference API access.
  • Mentions and preference requests now open a direct message with updated help guidance.

• Improvements

  • Updated installation links and simplified the OAuth callback experience.
  • Refreshed help text for translation, digest, and support options.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Free

Run ID: 4ad6fbbe-4a6d-4087-a9db-fb4c26a213dd

📥 Commits

Reviewing files that changed from the base of the PR and between f510bdc and 4efb643.

📒 Files selected for processing (6)

• api/internal/features/controller.go
• api/internal/httpapi/handler.go
• frontend/src/app/app-home/page.tsx
• frontend/src/app/oauth/callback/page.tsx
• frontend/src/app/page.tsx
• frontend/src/lib/api.ts

---

📝 Walkthrough

Walkthrough

Slack OAuth now passes Slack identity parameters into the App Home, which loads and updates user preferences through new Slack-based APIs. Slack help responses move to user DMs, and the help content is updated.

Changes

OAuth and preferences

Layer / File(s)	Summary
OAuth routes and Slack identity APIs api/internal/httpapi/handler.go	Adds OAuth initiation, updates callback token exchange and redirects, and provides Slack-based user and preference endpoints.
Slack identity client contract frontend/src/lib/api.ts	Updates preference types and helpers to use Slack user/team identifiers and adds user API helpers.
App Home loading and OAuth entry points frontend/src/app/app-home/page.tsx, frontend/src/app/oauth/callback/page.tsx, frontend/src/app/page.tsx	Loads and saves preferences through the new APIs, handles OAuth callback redirects, and routes installation CTAs through the backend OAuth start endpoint.

Slack help interactions

Layer / File(s)	Summary
DM help response flow api/internal/features/controller.go	Mention and preference handlers open user DMs before posting help blocks, with revised translation, digest, and support text.

Estimated code review effort: 4 (Complex) | ~45 minutes

Sequence Diagram(s)

sequenceDiagram
  participant Browser
  participant OAuthStart
  participant Slack
  participant OAuthCallback
  participant AppHome
  participant PreferenceAPI

  Browser->>OAuthStart: Request OAuth start
  OAuthStart->>Slack: Redirect to Slack authorization
  Slack->>Browser: Return authorization code
  Browser->>OAuthCallback: Forward code to backend
  OAuthCallback->>Slack: Exchange code for token
  OAuthCallback->>Browser: Redirect with Slack user and team IDs
  Browser->>AppHome: Load App Home
  AppHome->>PreferenceAPI: Get preferences and user
  PreferenceAPI-->>AppHome: Return preference data
  AppHome->>PreferenceAPI: Update preferences and user

Loading

---

Note

🎁 Summarized by CodeRabbit Free

Your organization is on the Free plan. CodeRabbit will generate a high-level summary and a walkthrough for each pull request. For a comprehensive line-by-line review, please upgrade your subscription to CodeRabbit Pro by visiting https://app.coderabbit.ai/login.

_{Comment @coderabbitai help to get the list of available commands.}