Refresh provider-first docs and fix DocFX navbar

[cwinland]

Summary

• refresh the provider-first documentation set across the root README, conceptual docs, migration guidance, cookbook, and samples
• fix the Help site DocFX navbar/header behavior by adding a recovery script for async navbar injection and collapse timing
• regenerate the published Help and API outputs, and update the docs release line to 4.3.0
• remove deprecated GetMock<T>() from the README common entry-point list so the main entry surface reflects the preferred APIs

Validation

• ran scripts/Generate-ApiDocs.ps1
• DocFX build succeeded with 0 warnings and 0 errors

[Copilot]

Pull request overview

Refreshes the FastMoq v4 “provider-first” documentation set (including migration guidance) and updates the DocFX-generated Help/API outputs, adding a client-side recovery script to stabilize the DocFX navbar/header behavior and bumping the docs line to 4.3.0.

Changes:

• Updates site navigation and conceptual docs to emphasize provider-first patterns, including “tracked vs standalone” (GetOrCreateMock<T>() vs CreateStandaloneFastMock<T>() / CreateFastMock<T>()) and related migration guidance.
• Fixes DocFX header/navbar behavior by injecting styles/fastmoq-docs.js via the DocFX template head partial.
• Regenerates Help/ and api/ outputs and updates version references to 4.3.0.

Reviewed changes

Copilot reviewed 232 out of 233 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
toc.yml	Adds “Provider capabilities” and introduces “Examples and Recipes” with a Cookbook entry in the DocFX TOC.
index.md	Updates the documentation landing page to 4.3.0 and adds provider-first guidance links (including Cookbook).
README.md	Updates the root README entry-point list to reflect preferred provider-first APIs (adds standalone vs tracked creation notes).
docs/README.md	Adds a direct link to the “Tracked vs standalone” section and bumps docs version line to 4.3.0.
docs/whats-new/README.md	Updates “What’s new” content/version to 4.3.0 and adds notes about tracked vs standalone guidance.
docs/getting-started/testing-guide.md	Adds sections clarifying tracked vs standalone fast mocks and documents MockModel equality semantics.
docs/migration/README.md	Adds migration guidance for using CreateStandaloneFastMock<T>() when needing an extra detached same-type double.
docs/migration/api-replacements-and-exceptions.md	Updates legacy API replacement table and examples to distinguish tracked vs standalone creation.
docs/samples/README.md	Updates samples overview to document tracked vs standalone mock usage patterns.
docs/samples/testing-examples.md	Adds an explicit “Tracked vs standalone” section and example snippet.
docs/api/quick-reference.md	Updates quick reference to point to Mocker for tracked/standalone creation APIs and adds MockModel equality note.
docs/api/index.md	Adds IFastMock<T> / MockModel<T> to quick lookup and clarifies tracked vs detached API location.
docfx-template/partials/head.tmpl.partial	Injects styles/fastmoq-docs.js into all generated pages to stabilize navbar/header behavior.
api/**.yml	Regenerated API reference YAML outputs.
Help/**	Regenerated published Help site HTML outputs (including TOC and pages) with the new script injected.