Improved context in lambda

[devhl-labs]

Fixes #151

Fix Stubble section lambda context for primitive-scoped sections

Problem

When a 3-argument section lambda (Func<dynamic, string, Func<string, string>, object>) is nested inside a boolean or other primitive-valued section, Stubble passes the primitive value (e.g. true) as the lambda's context argument instead of the actual data object. This causes the lambda to receive a useless value and fail to resolve any data paths.

Example template structure that triggers the bug:

{{#ringProgression}}          ← ringProgression = true
  {{#blockLambdas.groupBy}}   ← lambda receives `true` instead of the data dictionary
    ...
  {{/blockLambdas.groupBy}}
{{/ringProgression}}

The groupBy lambda needs the parent data dictionary to resolve array paths, but receives true and produces empty output.

Root Cause

In SectionTokenRenderer, the lambda dispatch code passed context.View directly to dynamic-context lambdas. When rendering inside a boolean section like {{#ringProgression}}, the context is pushed with the boolean value, so context.View is true.

Fix

Stubble.Core (SectionTokenRenderer.cs)

Added a FindNearestObjectView helper that walks up the context parent chain, skipping primitive views (bool, int, long, float, double, decimal, string), and returns the nearest ancestor view that is a real object (dictionary, hashtable, etc.). Both Write and WriteAsync use this instead of context.View when dispatching to dynamic-context lambdas.

private static dynamic FindNearestObjectView(Context context)
{
    var current = context;
    while (current != null)
    {
        var view = current.View;
        if (view != null && !(view is bool) && !(view is int) && !(view is long)
            && !(view is float) && !(view is double) && !(view is decimal)
            && !(view is string))
        {
            return view;
        }
        current = current.ParentContext;
    }
    return context.View;
}

When the lambda is inside an object section (e.g. a dictionary), FindNearestObjectView returns that dictionary directly — preserving existing scoped behavior.