Release v3.4.0

Summary

Implements issue #150: a self-contained template engine (Cratis.Templating) compatible with the dotnet new template.json format, and the cratis new command on top of it. Acquiring, rendering and finishing a template — including resolving Version="*" package references to concrete versions — works on a machine with no .NET installed at all. The engine core is derived from dotnet/templating (MIT) with attribution retained; no Microsoft.TemplateEngine.* dependency anywhere.

Added

• Cratis.Templating — a template engine implementing the full current template.json contract: all 24 published top-level properties plus globalCustomOperations/specialCustomOperations, all five symbol types, all 12 generators, the full value-form set, the four condition evaluators (C++, C++2, MSBuild, VB), conditional processing for every documented file family (including MSBuild Condition attributes), custom operations, constraints, baselines, localization overlays, and GUID replacement — with unknown constructs failing loudly by name rather than being ignored (#150)
• cratis new — lists the catalogued templates and instantiates them with dotnet-new compatible -n/-o semantics, dynamic parameter binding with choice validation, --parameters help, --dry-run, --force, interactive prompts with non-interactive equivalents, the explicit --allow-scripts yes|no|prompt contract for script post actions, and JSON output via --format (#150)
• Template package acquisition through the CLI's own NuGet v3 client — service index/flat container, NuGet.Config discovery with credentials, local folder feeds, an offline-capable disk cache under ~/.cratis/templates isolated from the dotnet template store (#150)
• All eight documented post actions implemented natively — package/project references added by editing project XML with versions resolved through the same NuGet configuration, .sln/.slnx written directly, file permissions, JSON properties, manual instructions, script execution under the explicit policy, and restore (the one toolchain-dependent action) reported with instructions when dotnet is absent (#150)
• Unit specs for the engine (expressions, conditionals, symbols, value forms, parsing, instantiation, post actions, globs, NuGet configuration and client, the package store, token replacement, file family detection, constraints, localization, baselines, placeholder filenames and GUID replacement), CLI specs for parameter binding, the catalogue and settings validation, and a conformance suite rendering vendored templates through the real engine (#150)
• The upstream Microsoft.TemplateEngine.TestTemplates corpus (MIT, 56 groups, 100 manifests) vendored at a pinned upstream commit with provenance recorded, and a phase-one conformance gate that parses every manifest: 98 parse cleanly, the two intentionally-invalid templates fail with named errors, and none fail silently (#150)
• cratis new --language — required when instantiating: csharp (C#; c# accepted), kotlin or java, case-insensitive. The language selects the template package and the template used when none is named — csharp instantiates the cratis template from Cratis.Templates today, and kotlin/java are wired for their coming cratis-kotlin/cratis-java packages, resolving to a named error until those publish (#150)
• cratis new --database — selects the database backend for the scaffolded application (mongodb default, plus postgresql, mssql, sqlite, matched case-insensitively). The selection becomes the template's Database parameter value — injected in the choice's canonical casing — so templates author database support like any parameter; templates without the parameter reject an explicit selection with a named error (#150)
• A differential oracle that renders the four Cratis templates through both this engine and dotnet new and diffs the trees — opt-in via CRA_TIS_DIFFERENTIAL=1, isolated DOTNET_CLI_HOME, and strictly a test-time oracle. It is green: all four templates render byte-equivalently to dotnet new, modulo generated GUIDs, resolved versions and years. Building it surfaced and fixed two real engine defects: a child-process pipe-drain deadlock in script/restore post actions, and add-reference fidelity (in-place Version="*" replacement preserving indentation, and honoring the documented targetFiles argument) (#150)
• Documentation: the creating-projects guide and template catalogue under Documentation/new/, a README section, THIRD-PARTY-NOTICES.md for the derived engine core, and SPECIFICATION.md recording the implemented contract version and source precedence (#150)

Changed

• The CLI solution gains the Cratis.Templating, Cratis.Templating.Specs and Cratis.Templating.Conformance projects; Cratis.Cli references the engine for the new command (#150)
• Manifest parsing now matches the upstream corpus exactly: case-insensitive property names with insignificant whitespace, precedence/rename/generatorVersions alternate forms, string-array post action arguments, boolean condition literals, and the legacy onlyIf/id/applyFileRenamesTo* properties accepted (#150)