refactor(lsp): effectify LSP service with InstanceState (#19150)

Author: kitlangton

packages/opencode/specs/effect-migration.md

@@ -186,5 +186,5 @@ Still open and likely worth migrating:
 - [ ] `SessionCompaction`
 - [ ] `Provider`
 - [x] `Project`
-- [ ] `LSP`
+- [x] `LSP`
 - [x] `MCP`