refactor(skill): canonicalize invocation policy

docs/cordis-catalog/services.md

@@ -1645,7 +1645,7 @@ registerProvider(provider: SkillProvider): () => void
  * Register a borrowed readonly runtime skill. Project entries outrank runtime entries, which
  * outrank user entries. Same-name runtime entries are first-wins; a duplicate logs a warning and
  * receives a no-op disposer so it cannot remove the winner.
- * @param skill - the complete skill definition to expose for discovery.
+ * @param skill - the skill definition input; omitted invocation and provider fields receive defaults.
  * @returns the exact Cordis effect disposer, preserving composite teardown order and invalidating caches.
  */
 register(skill: SkillRegistration): () => void
@@ -1673,7 +1673,7 @@ async get(name: string, options: SkillLookupOptions = {}): Promise<SkillDefiniti
 
 Types: [SkillDefinition](../core-data-structures/skills.md) · [SkillLookupOptions](../core-data-structures/skills.md) · [SkillProvider](../core-data-structures/skills.md) · [SkillRegistration](../core-data-structures/skills.md) · [SkillSummary](../core-data-structures/skills.md)
 
-Source: [`packages/skill/skill/src/index.ts:167`](../../packages/skill/skill/src/index.ts)
+Source: [`packages/skill/skill/src/index.ts:172`](../../packages/skill/skill/src/index.ts)
 
 ## `ctx.spillStore` — `SpillStore` (abstract seam)