v1.0.0-rc6

Sixth release candidate: the hash-rocket syntax that #867 accidentally reinstated is removed again, the CLI moves to urfave/cli, and the language server becomes a real documentation surface.

Removed: hash rocket (=>) syntax, again. Rockets in hash literals and shape annotations are parse errors with a single targeted diagnostic. The arbitrary-key runtime model stays: colon keys, index assignment for runtime-computed keys, and colon shape fields (label, string, symbol, and quoted-symbol names) are the supported spellings. Rescue bindings (rescue RuntimeError => err) are unaffected.

Added: language server documentation. Hover and completions now serve real docs parsed from the embedded references — kernel builtins, namespaces and their members through both accessors (Math.PI, Math::PI), keywords, and the stdlib member surface (386 entries, with merged multi-receiver sections and composed bang variants). User-defined functions, classes, modules, and enums hover with reconstructed typed signatures plus leading doc comments, resolved by scope and receiver kind. Drift gates keep the docs honest: every engine-registered builtin, parser keyword, and universal-member claim is enforced against the runtime.

Changed: the vibes CLI is rebuilt on urfave/cli with a stable command contract.

Editor note: the tree-sitter grammar v0.3.1 and editor extensions (zed 0.0.4, sublime 1.0.0) pair with this release — update your vibes binary to get documented hovers.