docs: establish Corp v1 Guild architecture

docs/architecture-high-level/overview-skills.mdx

@@ -20,6 +20,7 @@ The central sources live in [`home-v1-skills-code-agent`](https://gitea.lego-clo
 | Skill | Purpose |
 |---|---|
 | [`corp-v1--main`](https://gitea.lego-cloud.eu/home-v1-skills-code-agent/corp-v1--main) | Board authority, project lifecycle, resource model, membership, adoption, publication, and verification rules. |
+| [`corp-v1--guild`](https://gitea.lego-cloud.eu/home-v1-skills-code-agent/corp-v1--guild) | Cross-channel improvement intake, impact inventory, ownership routing, coordinated rollout, and convergence verification. |
 | [`corp-v1--glossary`](https://gitea.lego-cloud.eu/home-v1-skills-code-agent/corp-v1--glossary) | Shared terminology and rules for keeping canonical definitions in project documentation. |
 | [`corp-v1-channel-general`](https://gitea.lego-cloud.eu/home-v1-skills-code-agent/corp-v1-channel-general) | Onboarding, coordination, questions, and outcome broadcasts. |
 | [`corp-v1-channel-scope`](https://gitea.lego-cloud.eu/home-v1-skills-code-agent/corp-v1-channel-scope) | Ideas, Epics, Features, value, acceptance outcomes, and human solution approval. |
@@ -38,6 +39,8 @@ Every project owns fourteen adopted repositories in `corp-v1-<code>-skills-code-
 
 A project adoption records the central source branch and commit, then adds the project code, repository links, environment namespace, approved authority, and operating lessons. Central updates are compared and adopted semantically; they never silently overwrite project-specific decisions or authorization overrides.
 
+`corp-v1--guild` remains central because it coordinates improvements across projects. It is not copied as a fifteenth project skill and does not replace any mapped project channel skill.
+
 At runtime, a focused channel session loads its mapped project channel skill plus only the engineering or global skills needed for the current work.
 
 ## Mandatory engineering skills