Silex v0.45.0

Why upgrade?

This release prepares package publishing and installation through the
Cloudflare registry. It can publish a snapshot of a local directory without a
Git repository and keep versions installable independently of the author's
repository. It also adds language expressions and extends the LLVM backend
qualified on macOS ARM64.

Changes

• silex login authenticates authors through their GitHub identity without
  repository access; silex logout revokes the local credential.
• silex publish <directory> sends sources and declared artifacts to the
  registry. --dry-run lists included and excluded files and the snapshot
  digest without network access or publication.
• silex install detects the Cloudflare registry protocol when it is enabled
  on the official domain, verifies downloaded objects, and keeps access to
  the old index during the transition.
• The language supports value-producing match expressions, scalar literal
  patterns, and user-defined arithmetic operators.
• LSP completion covers more incomplete expressions, inherited members, and
  workspace changes.
• LLVM becomes the default backend on qualified macOS ARM64 hosts; other
  platforms keep the native backend by default. The native ARM64 and X64 paths
  also receive fixes and optimizations.

Impact and migration

The Cloudflare registry must be active on registry.silex-lang.org before
silex publish can upload. Before the cutover, --dry-run works offline and
installs continue to read the old index. After the cutover, older Silex clients
cannot install versions stored only on Cloudflare: update the client. Packages
can now be published from a directory without Git; a repository link remains
optional for contributors. Existing source code needs no change to use the
new language constructs.