Update to Pudu 0.1.3: derives in documentation, reference, and prompts #11

Bring the server up to Pudu 0.1.3, whose headline feature is derives.

Found against 0.1.3:

• The bundled documentation predates 0.1.3: there is no Derives chapter, no Deploying chapter, no 0.1.2 or 0.1.3 release notes, and no derives example; pudu_docs_search for "derives" finds nothing.
• pudu_module_reference Std.Meta omits FieldAccess.get, set, has, and attributeOr — the calls every derive strategy is written with — because trait and implementation methods are filtered by the module's export list.
• Types and traits are listed without their declarations, so a type's fields and its derives clause never reach the client.
• export derive strategies (Show, Eq, Ord, Hash, Json.Encode, Json.Decode, Row) are absent from the reference, because the compiler's JSON output omits them (chrismichaelps/pudu-lang#458).
• The prompts teach no derive rules, and CI and the language range still name 0.1.1.

Acceptance:

• The corpus is regenerated from pudu-lang v0.1.3.
• The reference lists trait and implementation methods of exported traits and types, each type and trait with its declaration, and every derive strategy with its doc comment.
• The prompts carry the derive rules; the server uses derives where its own records are encoded or decoded as JSON.
• pudu check, fmt --check, lint, test, and the mutation gate pass on Pudu 0.1.3; 0.1.2 is released.