chore: harden automation and refresh project documentation

[TrapEmAll]

Summary

This pass turns the newly expanded UnityScraper codebase into a cleaner, safer, and more maintainable project for contributors and release users.

• rewrites the README and advanced documentation around the current Library, Knowledge, Backup, CLI, API, and packaging workflows
• adds architecture, API, changelog, contribution, security, conduct, and license documentation
• adds Windows/Linux CI, Windows executable smoke builds, Dependabot, version consistency checks, and tag-driven release packaging with SHA-256 checksums
• removes generated binaries, local portable-mode state, duplicate dependency notes, and obsolete integration summaries from source control
• repairs the Windows setup and launcher scripts and makes the canonical PyInstaller build reproducible
• hardens the REST API with localhost defaults, token requirements for remote binding, restricted CORS, input limits, safe configuration allowlists, and generic server errors
• hardens backup copy/export behavior against path escapes, unsafe destinations, conflicting existing files, and abandoned FTP partial uploads
• fixes delayed Tk error callbacks, update-check result handling, checksum imports, and zero-time ETA calculations
• removes import-time writes to the user profile so modules and tests can be imported safely

Migration notes

• portable.mode is no longer committed. Source checkouts now use %LOCALAPPDATA%\UnityScraper by default. Users who want portable storage can create an empty portable.mode file beside the application or set UNITYSCRAPER_PORTABLE=1.
• Existing portable data under UnityScraperData is not moved automatically.
• dist/UnityScraper.exe is removed from Git history going forward. Release binaries should be downloaded from GitHub Releases or generated by the documented build script.
• Remote API bindings now require UNITYSCRAPER_API_TOKEN or --api-token. Localhost operation remains straightforward and /api/health remains unauthenticated.
• The project is declared GPL-3.0-only. Imported source material retains its own attribution and licensing metadata.

Source and transport considerations

• XboxUnity remains explicitly HTTP-only. This change does not add, prefer, or advertise HTTPS for XboxUnity endpoints.
• ConsoleMods, XenonLibrary, Free60, Redump, and No-Intro data remain source-attributed through the normalized knowledge model; this pass documents those boundaries and does not redistribute game content, firmware, keys, or SDK material.

Validation

• Ruff high-confidence checks: passed
• Python compile check: passed
• Core tests: 53 passed
• Integration tests: 31 passed
• Version consistency: 0.10.0b1 passed
• Windows PyInstaller one-file build: passed
• SHA-256 checksum generation: passed
• local Markdown link validation: passed

Next steps

• continue expanding structured XenonLibrary and Free60 parsers while preserving revision provenance and source licenses
• add user-selected Redump and No-Intro DAT import workflows with field-specific conflict resolution
• add signed release artifacts and a formal upgrade/migration assistant
• split the legacy monolithic test files into focused offline unit and integration suites