LSP publishes graphitron:dev compile diagnostics against generated-file URIs

R410’s Surfacing compile diagnostics section named three consumers for the incremental-compile round’s diagnostics: the console dev-loop block, the MCP diagnostics tool, and the LSP publishing them against the generated file’s URI (best-effort, so an editor with that generated .java open shows the javac error inline). R410 shipped the first two; the diagnostics already land on Workspace.compileDiagnostics() (in the LSP module) after every round, but no LSP textDocument/publishDiagnostics is emitted for them. Close the gap: on each setCompileDiagnostics swap, publish the round’s error diagnostics against the generated-file URIs and clear diagnostics that resolved. CompileDiagnostic.file() now carries a canonical file:// URI (normalised once at the javac boundary, the same spelling the schema channel publishes under), so the resolution step starts from a URI rather than a raw path to resolve under the generated-sources root. Best-effort per the R410 spec: an unresolvable entry (the (no source) sentinel, or a URI outside the generated tree) is skipped, not an error.