[Application Builder] Deliver templates, Blazor Hybrid composition, and adoption guidance

## User story

As a WinForms developer, I want supported templates and composition examples for basic, hosted, migration, enterprise, system-tray, and Blazor Hybrid applications so that I can adopt the Application Builder correctly without reverse-engineering its architecture.

## Rationale and user benefit

Templates are executable guidance and must reflect stable APIs, language parity, deployment realities, and secure defaults. This integration stream should consume the foundation work rather than duplicate hosting, DI, or configuration logic.

## Scope boundary

Own project/solution templates, Blazor Hybrid composition, migration samples, template metadata/discovery, and adoption documentation. Do not introduce new foundation APIs solely to simplify a template without review.

## Acceptance criteria

- [ ] Basic C# and VB templates produce equivalent application structure.
- [ ] Blazor Hybrid uses one coherent service provider, lifetime, logging, and configuration model.
- [ ] Migration and enterprise examples demonstrate incremental adoption.
- [ ] Templates build, run, publish, and remain Designer-compatible.
- [ ] Generated projects use secure, maintainable defaults and explain optional complexity.

## Definition of Done

- [ ] Template scope is reviewed after foundation contracts stabilize.
- [ ] Generated output, tests, samples, documentation, localization/accessibility, publishing, and upgrade guidance are complete.
- [ ] Template installation, creation, restore, build, run, publish, and cleanup are validated in CI.

## Parallelization

This is an integration stream. It can design scenarios early, but final implementation follows stable contracts from streams A-C to avoid churn and merge conflicts.

Start by reviewing the foundation contracts from streams A-C and the requested basic, hosted, migration, enterprise, system-tray, and Blazor Hybrid scenarios. Validate the generated projects through installation, creation, restore, build, run, publish, cleanup, and CI, with completion covering samples, documentation, localization/accessibility, publishing, and upgrade guidance.

Written by the indexing model from the issue text.