feat: centralized secrets management (#289)

docs/SECRETS.md

@@ -0,0 +1,106 @@
+# Secrets Management
+
+This document describes how SolarProof manages secrets across all environments.
+
+## Principle
+
+No secrets are committed to the repository. Three tiers:
+
+| Environment | Where secrets live |
+|---|---|
+| Local development | `apps/web/.env.local` (gitignored) |
+| CI/CD (GitHub Actions) | GitHub Actions secrets |
+| Production / Staging | Vercel environment variables |
+
+---
+
+## Required secrets
+
+| Variable | Description | Environments |
+|---|---|---|
+| `NEXT_PUBLIC_SUPABASE_URL` | Supabase project URL | All |
+| `NEXT_PUBLIC_SUPABASE_ANON_KEY` | Supabase public anon key | All |
+| `SUPABASE_SERVICE_ROLE_KEY` | Supabase service-role key (server-side only) | All |
+| `MINTER_SECRET_KEY` | Stellar secret key for the minter account | Local, CI, Staging |
+| `MINTER_SECRET_ARN` | AWS Secrets Manager ARN for minter key | Production |
+| `MINTER_PREVIOUS_SECRET_ARN` | ARN for previous key during rotation window | Production |
+| `REDIS_URL` | Redis connection URL for job queue | All |
+| `UPSTASH_REDIS_REST_URL` | Upstash REST URL for caching layer | Staging, Production |
+| `UPSTASH_REDIS_REST_TOKEN` | Upstash REST token | Staging, Production |
+| `NEXT_PUBLIC_ENERGY_TOKEN_ID` | Deployed energy_token contract ID | All |
+| `NEXT_PUBLIC_AUDIT_REGISTRY_ID` | Deployed audit_registry contract ID | All |
+| `NEXT_PUBLIC_COMMUNITY_GOVERNANCE_ID` | Deployed community_governance contract ID | All |
+
+---
+
+## Local development
+
+1. Copy the template: `cp apps/web/.env.example apps/web/.env.local`
+2. Fill in your values — never commit `.env.local`
+3. `.env.local` and `.env.*.local` are listed in `.gitignore`
+
+---
+
+## GitHub Actions (CI/CD)
+
+All secrets are stored in the repository's **Settings → Secrets and variables → Actions**.
+
+Secrets used in CI (`.github/workflows/ci.yml`):
+
+```
+NEXT_PUBLIC_SUPABASE_URL
+NEXT_PUBLIC_SUPABASE_ANON_KEY
+SUPABASE_SERVICE_ROLE_KEY
+MINTER_SECRET_KEY
+TURBO_TOKEN
+TURBO_TEAM
+```
+
+Staging-specific secrets (environment: `staging`):
+
+```
+STAGING_SUPABASE_URL
+STAGING_SUPABASE_ANON_KEY
+STAGING_SUPABASE_SERVICE_ROLE_KEY
+STAGING_MINTER_SECRET_KEY
+STAGING_ENERGY_TOKEN_ID
+STAGING_AUDIT_REGISTRY_ID
+STAGING_COMMUNITY_GOVERNANCE_ID
+VERCEL_TOKEN
+VERCEL_ORG_ID
+VERCEL_PROJECT_ID_STAGING
+```
+
+---
+
+## Production (Vercel)
+
+Set the following in the Vercel project's **Settings → Environment Variables** for the `production` environment:
+
+- All `NEXT_PUBLIC_*` variables
+- `SUPABASE_SERVICE_ROLE_KEY`
+- `MINTER_SECRET_ARN` (points to AWS Secrets Manager; `MINTER_SECRET_KEY` is not used in production)
+- `MINTER_PREVIOUS_SECRET_ARN` (set during the 24-hour key-rotation grace window)
+- `AWS_REGION`
+- `REDIS_URL`
+- `UPSTASH_REDIS_REST_URL`, `UPSTASH_REDIS_REST_TOKEN`
+- `LOGTAIL_SOURCE_TOKEN`
+- `CORS_ALLOWED_ORIGINS`
+
+Production never uses a plaintext `MINTER_SECRET_KEY`. The key is fetched at runtime from AWS Secrets Manager via `MINTER_SECRET_ARN` (see `src/lib/secrets.ts`).
+
+---
+
+## Key rotation
+
+1. Generate a new Stellar keypair for the minter account.
+2. Store the new key as a new secret version in AWS Secrets Manager.
+3. Update `MINTER_SECRET_ARN` in Vercel to point to the new ARN.
+4. Set `MINTER_PREVIOUS_SECRET_ARN` to the old ARN for 24 hours (allows in-flight transactions to complete).
+5. After 24 hours, clear `MINTER_PREVIOUS_SECRET_ARN`.
+
+---
+
+## Secret scanning
+
+GitHub secret scanning is enabled on this repository. Pre-commit hooks run [gitleaks](https://github.com/gitleaks/gitleaks) to catch accidental secret commits before they reach the remote. See `.gitleaks.toml` and `.pre-commit-config.yaml`.