Feature/simple file server with node18 support

[marioserrano09]

No description provided.

[Copilot]

Pull request overview

Version bump from 26.5.0 to 26.5.1 across all Maven and npm packages, with two functional changes targeting Node 18 support and embedded usage of simple-file-server, plus a small refactor in RemoteEntityFileStorage.

Changes:

• Bump all module versions (Maven pom.xml, npm package.json, lockfiles) from 26.5.0 → 26.5.1.
• simple-file-server: lower Node engine requirement to >=18.17.0, downgrade file-type to ^20.0.0, startServer now returns SFSRuntime, CLI prints environment info / server summary, README + embedded-mode example added.
• RemoteEntityFileStorage.fetchResource: simplify to restClient...body(Resource.class) instead of manually wrapping an InputStream in InputStreamResource.

Reviewed changes

Copilot reviewed 62 out of 65 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pom.xml, themes/**/pom.xml, platform/**/pom.xml, extensions/**/pom.xml, examples/demo-zk-books/pom.xml	Parent / dependency version bumps to 26.5.1.
platform/packages/*/package.json, platform/packages/*/package-lock.json, extensions/**/packages/*/package.json	npm package version bumps to 26.5.1.
extensions/entity-files/packages/simple-file-server/package.json + package-lock.json	Lower engines to Node ≥18.17, downgrade file-type to ^20, lockfile resolves matching @tokenizer/inflate and fflate.
extensions/entity-files/packages/simple-file-server/src/runtime/index.ts	startServer now returns the SFSRuntime after listening.
extensions/entity-files/packages/simple-file-server/src/cli/index.ts	Print env/system info and post-start summary of buckets and identities; CLI version bump.
extensions/entity-files/packages/simple-file-server/README.md	Add Requirements, Embedded Usage, exports, env-var docs; update Node minimum.
extensions/entity-files/packages/simple-file-server/examples/embedded/{package.json,index.js}	New embedded-mode example.
extensions/entity-files/sources/core/.../RemoteEntityFileStorage.java	Use body(Resource.class) directly instead of InputStream + manual InputStreamResource wrap.
examples/demo-zk-books/src/main/java/mybookstore/repositories/BookRepository.java	Remove unused imports.

Files not reviewed (3)

• extensions/entity-files/packages/simple-file-server/package-lock.json: Language not supported
• platform/packages/cli/package-lock.json: Language not supported
• platform/packages/sdk/package-lock.json: Language not supported