Backport patchrightInitScript route flag plumbing

[missin9]

Summary

This mirrors the route fallback and continue plumbing from Kaliiiiiiiiii-Vinyzu/patchright-python#115 for Patchright.NET.

Patchright init-script injection rewrites document requests through the internal patchright-init-script-inject.internal sentinel. The driver has a patchrightInitScript path that treats this as internal init-script traffic and continues with response interception. The .NET binding patcher did not pass that flag through route fallback and continue, so the sentinel could reach normal network or proxy handling.

Changes

• Adds RouteFallbackOptions.PatchrightInitScript.
• Copies the flag through fallback override application.
• Sends patchrightInitScript in route continue and fallback protocol params.
• Marks the generated Page and BrowserContext init-script fallback route with PatchrightInitScript = true.

Validation

• Built a local package from this patch with Patchright driver 1.60.0.
• Confirmed the generated source contains the flag in route options, fallback overrides, route protocol params, Page injection, and BrowserContext injection.
• Consumed the package from a downstream .NET Patchright application.
• Verified baseline browser launch.
• Verified AddInitScript still lands on a strict-CSP page through DOM reflection.
• Verified real HTTPS navigation through an authenticated residential proxy via a local HTTP CONNECT forwarder no longer fails with ERR_NAME_NOT_RESOLVED or ERR_EMPTY_RESPONSE from the internal init-script sentinel.
• Verified multiple all-proxied browser contexts in one Chrome process can navigate with distinct proxy sessions and context-level identity settings.

Notes

This keeps the .NET binding behavior close to patchright-python#115 and relies on the existing driver-side patchrightInitScript handling.