Feature/shortcuts and envdiff

[DevSars24]

Summary

This PR adds two features to the DebugProbe dashboard:

• Keyboard shortcuts for faster navigation without using the mouse.
• An automatic Environment Diff Badge that flags when the same endpoint behaves differently across environments (for example, staging versus production).

Both changes are additive and introduce no breaking changes.

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Feature 1: Keyboard Shortcuts

Added a single global keyboard listener so developers can navigate the dashboard faster:

• Pressing the forward slash key focuses the search box.
• Pressing Escape closes the currently open details panel, or blurs the search box if that's what's focused.
• Pressing the letter c copies the currently open trace as a cURL command.

Safety checks included:

• Shortcuts are automatically disabled while typing inside any text field, so pressing c or slash while searching just types normally instead of triggering an action.
• The only exception is Escape, which always works, even while typing.
• Modifier key combinations like Ctrl, Cmd, or Alt are ignored, so existing browser shortcuts are not affected.
• Holding a key down does not repeatedly re-trigger the same action.

This is a purely client-side change, implemented entirely in debugprobe-ui.js. No backend code was touched.

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Feature 2: Environment Diff Badge

A common class of bug is when an endpoint works correctly in one environment but breaks in another, using the exact same request. This feature surfaces that automatically instead of requiring a developer to manually run a compare.

How it works:

• When two traces are captured for the same route and HTTP method but from different environments, the dashboard compares their responses.
• The comparison uses the existing comparison engine that already powers the manual compare feature — no new diffing logic was written.
• If a genuine difference is found, a small badge appears next to that request in the dashboard.

Configuration:

• This feature is opt-in and disabled by default, controlled by a new setting called AutoEnvironmentDiff.
• When left disabled, no comparison work runs at all, and the dashboard behaves exactly as it did before this change.
• Developers can enable it explicitly if they want the automatic detection.

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Files Changed

• debugprobe-ui.js — added the keyboard shortcut listener.
• HtmlRenderer.cs — added the logic to detect and render the environment diff badge.
• DebugEntryStore.cs — now tracks which environment each captured request came from, needed to compare across environments.
• DebugProbeOptions.cs — added the new AutoEnvironmentDiff setting.
• debugprobe.css — added styling for the new badge, matching the existing visual design.
• HtmlRendererEnvDiffTests.cs — new test file covering the badge logic under different scenarios.

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Testing Done

• The project builds cleanly with no errors.
• All 96 tests pass, including the new tests written for this feature.
• Manually verified that with the new setting left at its default (off), no badge appears anywhere in the dashboard — confirming no change in behavior for existing users.
• Manually tested all three keyboard shortcuts in the browser:
  • Search focus works correctly.
  • Closing the details view works correctly.
  • Copying a trace as cURL works correctly.
  • Typing normally inside the search box is unaffected.

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