feat: ship the v0.3 guided installer and review workflow

[snss10]

Summary

TextRecast v0.3.0 replaces the portable first-run experience with one guided, model-free Windows installer and adds an explicit review/edit step before source text can be replaced.

What changed

Guided Windows setup

• Added a self-contained per-user setup host and internal NSIS package.
• Added license/privacy acceptance, destination selection, explicit model choice, ready, installing, and completion screens.
• Downloads only the selected model and preserves resumable, size-checked, SHA-256-verified installation.
• Added package-owned Start Menu, optional Desktop, and optional Windows Startup shortcuts.
• Added transactional payload replacement, rollback/recovery, quiet commands, and scoped uninstall ownership.

Review-before-replacement workflow

• Keeps the captured source unchanged while generation runs.
• Shows fixed Original and editable Revised panels.
• Supports Regenerate, Copy, Cancel, and explicit Replace selection actions.
• Closes the editor after a clean replacement.
• Preserves the editor, revision, and message after failure, cancellation, or a clipboard-restoration warning.
• Restores the v0.2-style launcher toggle: click once to open, click again to close without recapturing.

Windows UI and information surfaces

• Added one compact Windows-controlled light/dark visual system across setup and application windows.
• Added a rounded-square floating launcher and compact themed context menu.
• Added consistent Model information, Legal & Privacy, and About dialogs.
• Removed the old first-launch model-selection/download windows in favor of setup recovery.

Release and documentation

• Updated the application version to 0.3.0.
• Updated README, privacy, model, installer, third-party, and security documentation.
• Added v0.3.0 release notes.
• Changed GitHub Actions to publish one supported model-free installer plus its checksum.

Verification

• dotnet format TextRecast.slnx --verify-no-changes --no-restore
• Release build completed with 0 warnings and 0 errors.
• 177 automated tests passed: 5 Core, 60 Deployment, 71 Infrastructure, 33 Setup, and 8 App.
• Exact committed-source installer reports version 0.3.0+8a9b957eed4c85536bf9edb4b0a8c92808140572.
• Installer payload contains all required legal/runtime notices and no GGUF or partial model files.
• Local installer SHA-256 verified: c61b93438ac9fea057401ba987c90c6cab0503a27ecfa26413b010ea384335eb.
• Required PR checks pass on GitHub Actions.
• Final clean-profile test is completed using the artifact from the successful tag workflow.

Current boundaries

• Windows x64 only.
• CPU inference through LLamaSharp.
• Current catalog profiles target English rewriting.
• Local models can change meaning or details; every revision should be reviewed before replacement.
• The Microsoft Visual C++ x64 Redistributable may be required.

Screenshots