fix: add adaptHostSkillConfig utility for host config.skills.paths

Converts the host OpenCode config.skills object (with paths/urls arrays set by other plugins like superpowers) into the SkillsConfig format used by discoverConfigSourceSkills. Filters blank/whitespace entries and non-string values.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/shared/host-skill-config.ts

@@ -0,0 +1,28 @@
+import type { SkillsConfig } from "../config/schema/skills"
+
+type HostSkillConfig = {
+  paths?: unknown
+  urls?: unknown
+}
+
+function toStringArray(value: unknown): string[] {
+  if (!Array.isArray(value)) return []
+  return value
+    .filter((item): item is string => typeof item === "string")
+    .map((item) => item.trim())
+    .filter((item) => item.length > 0)
+}
+
+export function adaptHostSkillConfig(value: unknown): SkillsConfig | undefined {
+  if (!value || typeof value !== "object") return undefined
+
+  const hostSkillConfig = value as HostSkillConfig
+  const sources = [
+    ...toStringArray(hostSkillConfig.paths),
+    ...toStringArray(hostSkillConfig.urls),
+  ]
+
+  if (sources.length === 0) return undefined
+
+  return { sources } as SkillsConfig
+}