The Analyze panel showed each signature as a flat string, so the type names
that carry the key information were hard to spot in long Used-By / Uses lists.
Render analyzer entity rows as syntax-highlighted rich text with the type-name
spans emboldened (issue #2164).
Replace Language.GetRichTextTooltip(entity) with a general
GetRichText(entity, conversionFlags, boldTypeNames): the hover tooltip is one
caller, the analyzer pane another. C# colours the signature via
CSharpHighlightingTokenWriter and bolds the type-name colour spans; IL renders
its disassembled header (its signature form), already lexically highlighted;
the base produces plain text. The IL method/type/field header is semantically
the same artifact as the C# signature, so it shares the one method.
Rendering is opt-in: nodes that want rich labels implement IRichTextNode, and
the single shared SharpTreeView cell renders its runs via the new RichNodeText
attached behaviour, falling back to the plain Text otherwise. SharpTreeNode.Text
stays the authoritative plain string, so search, copy and keyboard navigation
are unchanged; analyzer entity nodes derive Text from the same RichText so the
two never diverge.
Fixes#2164
Assisted-by: Claude:claude-opus-4-8:Claude Code