Update vscode-languageclient to v10

[jakebailey]

This has two negative effects:

• All of our current logging appears as "error" output because it went over stderr.
  • "Fixed" by introducing leveled logging.
• All LSP logging is hidden by default, which is perhaps good for end users but sort of annoying for debugging.
  • related: Ability to set log levels by output channel vscode#223536
  • You can at least select the "default" log level for a channel, which will persist. That's probably good enough for regular debugging.

But, fixes client bugs we've experienced.

[Copilot]

Pull request overview

This PR updates the VS Code language client from v9 to v10.0.0-next.18 and introduces leveled logging to properly integrate with the new client version. The main motivation is that vscode-languageclient v10 treats all stderr output as errors, so the update includes adding Info/Warn/Error logging levels that map to LSP log message types.

Key Changes:

• Update vscode-languageclient to v10.0.0-next.18 (and VS Code engine to 1.106.0)
• Add leveled logging methods (Error, Warn, Info) to the Logger interface
• Create LSP-specific logger that sends log messages via LSP protocol
• Remove unused ServerOptions fields (Client, Logger)

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
package-lock.json	Updates vscode-languageclient and related dependencies to v10, adjusts dev dependency flags
_extension/package.json	Updates vscode-languageclient to v10.0.0-next.18 and VS Code engine to 1.106.0
_extension/src/extension.ts	Changes output channels to use LogOutputChannel type with log: true option
_extension/src/client.ts	Updates to use LogOutputChannel and adds hint about trace log level
internal/project/logging/logger.go	Adds Error/Warn/Info leveled logging methods, removes Write() method
internal/project/logging/logtree.go	Adds Error/Warn/Info leveled logging methods, removes Write() method
internal/project/logging/logtree_test.go	Removes Write() from test interface
internal/lsp/logger.go	New LSP-specific logger that sends log messages via window/logMessage notifications
internal/lsp/server.go	Uses new logger, removes unused ServerOptions fields, replaces Log() calls with appropriate levels
internal/project/snapshot.go	Replaces Write() with Log()
internal/project/session.go	Replaces Write() with Log()
internal/lsp/lsproto/_generate/metaModelSchema.mts	Updates LSP meta model schema with new clientCapability and serverCapability fields
internal/lsp/lsproto/_generate/fetchModel.mts	Updates hash to fetch updated meta model from vscode-languageserver-node

[andrewbranch]

Don't love the changes that were pushed on us with this, but this implementation seems fairly non-disruptive

[jakebailey]

Alternatively, I can implement my own LogOutputChannel (it's just an interface) which logs to a non-log output, but I don't think that's going to work so well with the log level / event emitter :\

Probably best to acquiesce