docs(skill): document the user-explicit invocation path

Bilingual README updates for the four touched packages (ui-skill's claim
flow and deterministic-injection model experience, the apiproxy skills
domain, the shared renderSkillContent seam export, the catalog stitch
sentence), the implemented Agent Note triplet recording the decision and
its peer-product evidence, and the regenerated catalogs/graphs.

packages/skill/skill/README.md

@@ -37,6 +37,10 @@ This package owns the `ctx.skills` interface. It does not know whether skills co
 | `{ modelInvocable: false, userInvocable: true }` | excluded | included |
 | `{ modelInvocable: false, userInvocable: false }` | excluded | excluded |
 
+### Shared model-facing rendering
+
+`renderSkillContent(skill)` renders one loaded skill as the canonical `<skill_content>` block (escaped `name` attribute, resource hints, verbatim body). It is the single truth for both loading paths: `dsh-tool-skill` returns it as the `skill` tool result, and the host's user-explicit `skill.invoke` injects it as a user message, so the model sees one shape regardless of who initiated the load. `escapeText` is exported beside it for consumers embedding prose in the same markup frame. The package also declares the `skill-invocation` `MessageSource` kind ({ name, args? }) that user-explicit injection stamps on its messages — transcript consumers present the invocation from this metadata instead of re-parsing the body.
+
 `isModelInvocable(skill)` and `isUserInvocable(skill)` read the matching positive field directly. `ctx.skills.get()` remains the trusted, policy-neutral loading primitive, so every user- or model-facing consumer must enforce the predicate that matches its surface before exposing or loading a skill.
 
 ## Provider Contract