[StevenTCramer]

Summary

What changed

• Generator (operation-endpoint-extractor.json-string-types.cs, new): for each [Operation] JSON member
  the extractor walks the member type (type arguments, array elements, public instance properties of
  non-framework types, base types included) and records each type that has its own [JsonConverter]
  (string-enum converter excluded) and implements IParsable<TSelf>. IsUuid is set when it has a public
  instance Guid Value. Carried on OptionDefinition.JsonStringTypes (JsonStringType record, equatable).
• Emitter (capabilities-emitter.cs): passes them to NuruJsonMemberSchema.Create(..., stringTypes: [...], uuidTypes: [...]); members with none emit the old call unchanged.
• Runtime (nuru-json-member-schema.cs): Create gained optional stringTypes/uuidTypes. The
  transform rewrites an untyped node (true or a typeless object) of those types to {"type":"string"}
  (+ "format":"uuid"), ["string","null"] for Nullable<T> or a nullable reference property, and fills
  missing items / additionalProperties for collections and dictionaries of them (the exporter omits
  them). [Description] runs after, so it is kept. Done at compile time because timewarp-nuru is
  IsAotCompatible + trim analyzed: no GetInterfaces() reflection.
• Top-level typed-ID option (checked, was broken, fixed): an [Operation] property of a typed-ID type
  is not a scalar, so it is a JSON member (type json Ns.PrincipalId). Before: its schema was true
  (untyped) in --capabilities and McpHost, and the --json-args/MCP binder's kind gate accepted only an
  object or array, so every value was rejected (wrong JSON type. Expected json). Now the schema is
  {"type":"string","format":"uuid"} and the kind gate (json-args-emitter.validation.cs) takes a JSON
  string for a member whose own type is a typed ID (OptionDefinition.IsJsonStringValue; expected type
  reads string). Argv still rejects JSON members (--Owner is JSON. Pass it with --json-args.); accepting
  a typed ID on argv is a separate change, not done here.
• Tests: tests/timewarp-nuru-mcphost-tests/mcphost-08-typed-id-schema.cs (in CI multi-mode via the
  mcphost glob): test-local Guid-backed TidPrincipalId (record struct, converter writing the Guid string,
  ISpanParsable) and string-backed reference TidSlug. Covers top-level (capabilities option schema +
  McpHost inputSchema, non-null and nullable), array items, nested object with [Description], nullable
  struct, nullable reference without format, nested list, dictionary values, string-enum unchanged, and
  binding through --json-args and NuruMcpToolInvoker (good value, object rejected with Expected string, unparsable rejected as a bind error).
• Docs: documentation/user/features/agent-invocation.md (JSON member schema section),
  documentation/user/features/neutral-contracts.md (derivation table), changelog.md (Unreleased / Fixed).
• Out of scope, unchanged: other custom converters (e.g. Roslynk-style lenient converters) still publish
  untyped; property-level [JsonConverter] is not detected.
• Release: not cut. Version stays 4.0.0-beta.13 (released); ships in the next Nuru beta when one is asked for.

Gates

Gate	Command	Result
Build	./bin/dev build	pass, 0 warnings, 0 errors
Test	./bin/dev test (after ganda runfile cache --clear)	pass: multi-mode 2208 total, 2202 passed, 6 skipped, 0 failed; standalone 47 files, 0 failed
Audit	ganda repo audit	pass, 1 advisory (vscode-window-icon, gitignored .vscode/settings.json); ganda repo audit --fix fixed it, all checks pass

Test plan

Smoke:

ganda runfile cache --clear
cd tests/timewarp-nuru-mcphost-tests && dotnet run mcphost-08-typed-id-schema.cs

Expect: Passed: 3 (Should_publish_a_top_level_typed_id_as_a_uuid_string,
Should_publish_typed_ids_nested_in_arrays_objects_and_dictionaries,
Should_bind_typed_ids_through_json_args_and_mcp_arguments). The Owner schema is
{"type":"string","format":"uuid"}, Members.items is the same, Details.properties.Backup is
["string","null"], and tid-assign --json-args '{"Owner":"<guid>",...}' exits 0.

Kanban task 526
Session: Roslynk