Allow users to pause the proxy for a set duration (1/5/15/30/60 min)

[hanneshapke]

Summary

Add the ability to pause the proxy for a fixed amount of time. Users sometimes need to temporarily disable interception (e.g. to debug a connectivity issue, hit an endpoint that breaks under interception, or get unblocked quickly) without having to remember to turn the proxy back on. A timed pause that auto-resumes solves this.

User-facing behavior

In Settings, add a "Pause proxy" control:

• An on/off switch to pause/resume the proxy.
• When turning the pause on, the user picks a duration: 1, 5, 15, 30, or 60 minutes.
• While paused, traffic passes through untouched (no PII processing / interception).
• When the timer elapses, the proxy automatically resumes and the switch flips back to off.
• The UI should show that the proxy is paused and ideally a countdown / "resumes at HH:MM".
• Toggling the switch off manually resumes immediately before the timer elapses.

Suggested implementation

This feature extends the existing transparent-proxy enable/disable machinery rather than adding a parallel system.

Backend (Go)

• The gate already exists: TransparentProxy.IsEnabled() (src/backend/proxy/transparent.go:76) is checked first in ServeHTTP (transparent.go:84); when not enabled, traffic is passed through untouched. A pause = make this return false until a "paused-until" timestamp.
• Store a pausedUntil time.Time on the Server (next to transparentProxyEnabled / transparentProxyMu, src/backend/server/server.go:83-84) and have IsTransparentProxyEnabled() (server.go:928) also consult it. A background timer (or lazy check on each request) clears the pause when it expires.
• Add an endpoint modeled on handleTransparentProxyToggle (server.go:888), e.g. POST /api/proxy/pause with { "minutes": N } and a resume/clear variant.
• Decide whether the pause should also bypass the Playground/API path (Handler.ServeHTTP, src/backend/proxy/handler.go:154), which currently has no enabled gate — if so, add an early bypass check there too.

Persistence / scheduling (Electron)

• Mirror the defineConfigField("transparentProxyEnabled", ...) pattern (src/frontend/src/electron/ipc-handlers.js:476) and notifyBackendBestEffort so the pause survives a renderer reload. Persist the pausedUntil timestamp (not just a boolean) so the remaining time is accurate after a restart.

Frontend (React)

• Reuse the existing on/off switch UI from the Transparent Proxy toggle in AdvancedSettingsModal.tsx:206-240 (state at lines 30-31, handler handleToggleTransparentProxy lines 71-94, switch markup lines 213-225).
• Add the duration choices (1/5/15/30/60 min) as buttons or a select next to the switch.
• Surface the control from Settings (SettingsModal.tsx) or Advanced Settings, and show the paused state + countdown.

Notes / open questions

• Should the pause apply to both the transparent proxy and the Playground/API path, or only the transparent proxy?
• Where should the control live — main Settings or Advanced Settings?
• Should remaining pause time persist across app restart (recommended: yes, via a timestamp)?

There is currently no existing pause/timer/expiry concept in the codebase; the closest precedent is the transparent-proxy enable/disable toggle, which this should build on.