Request History

> ℹ️ _This issue was partially AI-generated and may contain technical inaccuracies._

**Is your feature request related to a problem? Please describe.**
Sent requests are not tracked. To revisit or re-send a previous call, the user must have saved it manually beforehand, which is easy to forget during exploratory work.

**Describe the solution you'd like**
Automatically record every sent request (URL, method, headers, body, timestamp, and response summary) in a History view where users can:
- browse past requests chronologically
- re-send a request with one click
- compare or promote a history entry into a saved request.

**Describe alternatives you've considered**
Relying on manually saving every request (current behaviour); browser-style 'recent' list without full detail.

**Additional context**
Needs a retention/limit policy and a clear-history action. Consider whether history is global or per-collection, and how it interacts with secret variables (do not persist resolved secrets).

No files or tests are named; start by locating the request-sending flow and the existing saved-request handling. Define the history view and its retention, clear-history, resend, comparison, and promotion behavior, while ensuring resolved secrets are not persisted; done requires agreement on global versus per-collection scope.

Written by the indexing model from the issue text.