Add host-configurable language service

doc/manual/souce/components.md

@@ -41,9 +41,21 @@ The WebAssembly package is for execution, not syntax highlighting.
 
 ## Language tools
 
-Source-level tooling lives in the Rust language tools crate.
+Semantic editor integration lives in the host-configurable language service crate.
+It depends only on the runtime and accepts the same `HostEnvironment` implementation used by a production application.
+A host-specific LSP binary can link this crate with its loader and global schema configuration without reimplementing evaluation rules.
+
+Important paths:
+
+```text
+crates/decodal-language-service/
+```
+
+Source formatting lives in a separate Rust language tools crate.
+Keeping it separate prevents host-specific semantic services from inheriting the formatter's Tree-sitter and WebAssembly dependencies.
+
 This component is responsible for operations that must preserve source text details such as comments and whitespace.
-It is an internal crate used by the future Rust LSP and by the CodeMirror package's bundled formatter WebAssembly.
+It is used by the CodeMirror package's bundled formatter WebAssembly and can also be used by an LSP adapter for formatting.
 
 Important paths:
 
@@ -52,7 +64,6 @@ crates/decodal-language-tools/
 ```
 
 The current language tools crate exposes the formatter.
-Future LSP functionality should build on the same source-level tooling layer rather than on the runtime core.
 
 ## Web editor components
 
@@ -112,7 +123,8 @@ Consumers that need syntax information should use the component that matches the
 - Rust execution and embedding: `decodal`
 - Browser execution: `decodal-wasm`
 - Web formatting and editor syntax: Lezer / CodeMirror
-- Rust LSP internals: `decodal-language-tools`
+- Semantic editor analysis: `decodal-language-service`
+- Rust formatting: `decodal-language-tools`
 - General editor syntax: Tree-sitter
 
 This avoids having a separate token stream API whose behavior would have to be kept compatible with both runtime parsing and editor grammars.