chore: Delete dead C# code

[reakaleek]

What

Remove code with zero callers, zero usages, or that is written but never read.

Items to delete

Svg tokens/ icon set — 56 files + all plumbing

GetToken, TryGetToken, and Tokens have zero references outside EuiSvgIcons.cs. Delete the 56 embedded token SVGs (svgs/tokens/*.svg) plus LazyTokenMap, the 57-entry TokenAliases dictionary, LoadTokens, and the tokens EmbeddedResource include in the csproj.
Files: src/Elastic.Documentation.Svg/EuiSvgIcons.cs, src/Elastic.Documentation.Svg/svgs/tokens/, src/Elastic.Documentation.Svg/Elastic.Documentation.Svg.csproj (~90 lines + 56 files)

IConversionCollector — zero implementations

Always null; the "used primarily for testing" comment is stale. Remove the interface and the null-threading (field, ctor param, ConversionCollector property, collector?.Collect(...) call) through DocumentationGenerator/HtmlWriter/DocumentationFileExporter.
File: src/Elastic.Markdown/DocumentationGenerator.cs:27 (~18 lines)

ICodexModel + ICodexPageRenderer — never implemented, never called

The RenderAsync calls in CodexGenerator are RazorSlices.RenderAsync, not this interface. Fully dead.
File: src/Elastic.Codex/CodexGenerator.cs:22 (~16 lines)

IValidator interface — entire file

Zero implementations and zero usages; pure dead letter.
File: src/api/Elastic.Documentation.Api/Validation/IValidator.cs (~12 lines)

ElasticsearchEndpoint — 4 unread properties

Set by the configurator but never read anywhere:

• SearchNumThreads
• IndexNumThreads
• BufferSize
• NoElasticInferenceService

File: src/Elastic.Documentation.Configuration/DocumentationEndpoints.cs:43-61 (~8 lines + assignments)

ConfigurationFile.DevelopmentDocs — unread property

Set from YAML field DevDocs, never read by any consumer. Delete the property, its assignment, and the DevDocs YAML field if unused elsewhere.
File: src/Elastic.Documentation.Configuration/Builder/ConfigurationFile.cs:88

CrossLinkValidator.GetExcludedSchemes() — zero callers

The field it would return is accessed directly everywhere; this method is never called.
File: src/Elastic.Documentation/Links/CrossLinkValidator.cs:68

~150 lines + 56 files removed across the batch.

Note

Re-audited 2026-07-07: added the Svg token set, IConversionCollector, and ICodexModel/ICodexPageRenderer (all grep-verified dead).

Part of the broader ponytail over-engineering audit tracked in #3574.

[reakaleek]

Part of the ponytail over-engineering audit tracked in #3574.