Refactor the TypeScript data flow for full type safety and auto-generation of Rust types (#3865)

* Migrate Specta to Tsify to auto-generate messages.ts, working except colors and widgets

* Adopt the generated FillColor/Color/GradientStops

* Fix widget typing

* Separate WidgetGroup enum variants into wrapper structs

* Small rename

* Simplify widgets further

* Clean up message type references

* Switch type imports to the auto-generated file

* Remove lowercase serde rename

* Fix FillChoice deserialization

* Fix small regression from #3837

* Improve type safety

* Make WidgetSpan type-safe

* More cleanup and type safety

* More type safety

* More type safety

* Get the rest to type-check without errors; improve widget builder macro to have optional icons; improve Svelte 5 configs

* Cargo fmt

* Fix imports

* Update outdated readme info

* Fix lint command rename references

* Fix typos

* One more typos fix

* Remove unnecessary dep: prefix from the edited Cargo.toml files

* Remove excess parts from Cargo.toml

* Fix compiling on desktop

* Revert "Remove excess parts from Cargo.toml"

This reverts commit 6b711117b3a5d5d8a3ee20f36a43bc74930b7c82.

* Update dev docs with simpler, more accurate instructions

node-graph/graph-craft/src/document.rs

@@ -452,7 +452,7 @@ pub struct OldDocumentNode {
 }
 
 // TODO: Eventually remove this document upgrade code
-#[derive(Clone, Debug, PartialEq, Default, specta::Type, Hash, DynAny, serde::Serialize, serde::Deserialize)]
+#[derive(Clone, Debug, PartialEq, Default, Hash, DynAny, serde::Serialize, serde::Deserialize)]
 /// Metadata about the node including its position in the graph UI
 pub struct OldDocumentNodeMetadata {
 	pub position: IVec2,