feat: switch to gen-lsp-types

[ribru17]

gen-lsp-types is an alternative to the lsp-types crate, with types generated via codegen from the official LSP Metamodel for correctness and completeness.

lsp-types issues fixed in gen-lsp-types:

• Add LSP 3.18 SnippetTextEdit support (proposed) gluon-lang/lsp-types#310
• Eq and Hash for all Param/Result types? gluon-lang/lsp-types#308
• The new Uri type in 0.96.0 is hard to use and have almost no interoperability gluon-lang/lsp-types#284
• Why type names of this crate don't follow the spec ? gluon-lang/lsp-types#278
• Auto-generate Protocol Bindings gluon-lang/lsp-types#277
• Derive Default for CodeActionOptions gluon-lang/lsp-types#260
• many types don't derive Hash even though they can gluon-lang/lsp-types#245
• FoldingRange.kind is limited gluon-lang/lsp-types#93

See rust-lang/rust-analyzer#22115 and wgsl-analyzer/wgsl-analyzer#1090 for other migration considerations

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Note

Medium Risk
Swaps the core LSP type definitions used across the server, which can subtly change JSON serialization/deserialization and capability wiring. Main risk is client-facing protocol incompatibilities if any renamed fields/enum variants don’t match expectations.

Overview
Switches the workspace’s lsp-types dependency to gen-lsp-types and updates both lsp and util crates to consume it via workspace dependencies.

Adjusts LSP handling code to the new generated type shapes (renamed enum variants, text_document_position_params field, Url→Uri, hover contents type, and capability construction), and updates Cargo.lock with the new crate and transitive dependency/version changes.

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