[APP] Signalbase (API-key auth, webhooks available for instant sources)

**Name of app / service**

Signalbase — https://www.trysignalbase.com

Disclosure: I'm the founder of Signalbase, so I can commit to maintaining the integration and to keeping the auth surface stable.

**Link to developer documentation**

https://docs.trysignalbase.com

Auth is a simple API key: `Authorization: Bearer `, base URL `https://www.trysignalbase.com/api/v2`. Keys are generated at https://www.trysignalbase.com/workspace/api. No OAuth, no per-account subdomain, so the app definition should be minimal.

**Is lack of support preventing you from moving forward, or do you have a workaround?**

There's a workaround today — users can hit us through Pipedream's HTTP request action — but it pushes auth handling and pagination onto every user individually. A first-class app would let Pipedream users drop Signalbase into a workflow without managing credentials by hand.

Signalbase is a real-time B2B signal API: funding rounds, acquisitions, hiring activity, job changes, investors, and company data. The natural Pipedream use case is triggering a workflow the moment a buying signal fires — enrich, route to CRM, notify a rep.

**Are there specific actions or triggers you'd like to see for this app?**

Actions (all `GET`, straightforward filter/paginate):
- Search funding signals — `/signals/funding`
- Search hiring signals — `/signals/hiring`
- Search job change signals — `/signals/job-changes`
- Search acquisition signals — `/signals/acquisitions`
- Search investors — `/investors`
- Search companies — `/companies`
- Submit CSV enrichment job — `POST /csv-enrichment` (async, poll for result)

Triggers: we support outbound webhooks as a first-class resource (`POST /webhooks`, plus `/webhooks/{id}/test`, `/webhooks/{id}/deliveries`, and delivery retry), so **instant** sources are viable rather than polling-only.

Two notes that may help whoever scopes this:
- `count=true` on the hiring and companies endpoints returns totals for **0 credits**, which makes it a safe no-cost endpoint for credential verification (we use it for exactly that in our Nango integration).
- `limit` caps at 100; pagination is `page` + `limit`.

Happy to write the app file and components myself once the app directory exists, and to provide a test account for whoever picks it up.

The issue names the Signalbase API base URL, endpoints, webhook resources, and pagination rules but no repository files or tests. Start in the app directory by examining a similar API-key app, then use the Signalbase documentation; done means the app authenticates, exposes the requested actions and webhook-based instant sources, and handles page/limit pagination.

Written by the indexing model from the issue text.