Set sourceType to skills_sh for skills imported from skills.sh URLs

When skills are imported via skills.sh URLs or key-style imports
(org/repo/skill), the stored sourceType is now "skills_sh" with the
original skills.sh URL as sourceLocator, instead of "github" with the
resolved GitHub URL.

- Add "skills_sh" to CompanySkillSourceType and CompanySkillSourceBadge
- Track originalSkillsShUrl in parseSkillImportSourceInput
- Override sourceType/sourceLocator in importFromSource for skills.sh
- Handle skills_sh in key derivation, source info, update checks,
  file reads, portability export, and UI badge rendering

Co-Authored-By: Paperclip <noreply@paperclip.ing>

ui/src/pages/CompanySkills.tsx

@@ -148,6 +148,8 @@ function sourceMeta(sourceBadge: CompanySkillSourceBadge, sourceLabel: string |
     normalizedLabel.includes("skills.sh") || normalizedLabel.includes("vercel-labs/skills");
 
   switch (sourceBadge) {
+    case "skills_sh":
+      return { icon: VercelMark, label: sourceLabel ?? "skills.sh", managedLabel: "skills.sh managed" };
     case "github":
       return isSkillsShManaged
         ? { icon: VercelMark, label: sourceLabel ?? "skills.sh", managedLabel: "skills.sh managed" }