docs: refactor 5 GeneralUpdate component docs with unified template (#77)

* docs: update API references from UpdateAuth to HttpAuth
>
> Reflects rename in GeneralUpdate Core library.
>
> Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs: refactor 5 GeneralUpdate component docs with unified template

Unified documentation structure for Core, Bowl, Differential, Drivelution,
and Extension across zh-Hans and en locales. Each doc now follows:

  §1 Component Overview with capabilities table, business problems & use cases
  §2 Feature list (Core/Extended classification)
  §3 API reference — 3 tables: Props, Methods, Callback Events
  §4 Advanced examples with extension points overview
  §5 Basic examples (quick start → basic params → production ready)
  §6 Global configuration

Additional changes:
- Added inline metadata (namespace, entry point, NuGet package) below title
- Removed redundant duplicate fields from Environment & Dependencies section
- Removed 'dotnet add package' install commands (redundant with metadata)
- Merged UpgradeHub content into GeneralUpdate.Core docs
- Updated sidebar to remove standalone UpgradeHub entry

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: JusterZhu