fix(skills): use slug for skill download URL from ClawHub (#502)

* fix(web): use slug for skill download URL from ClawHub

The skill install handler was using req.name (display name like
"Markdown Converter") instead of the slug (like "owner/markdown-converter")
when constructing the download URL. The registry endpoint expects a slug,
so display names caused 502 errors.

- Add optional `slug` field to SkillInstallRequest
- Prefer slug over name when building the download URL
- JS installSkill() now sends slug from search results

Closes #482

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: guard against empty slug string in skill download URL

Filter out empty slug strings so we fall back to name instead of
constructing an invalid download URL.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* style: cargo fmt

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

src/channels/web/handlers/skills.rs

@@ -148,7 +148,14 @@ pub async fn skills_install_handler(
             .await
             .map_err(|e| (StatusCode::BAD_REQUEST, e.to_string()))?
     } else if let Some(ref catalog) = state.skill_catalog {
-        let url = crate::skills::catalog::skill_download_url(catalog.registry_url(), &req.name);
+        // Prefer slug (e.g. "owner/skill-name") over display name for the
+        // download URL, since the registry endpoint expects a slug.
+        let download_key = req
+            .slug
+            .as_deref()
+            .filter(|s| !s.is_empty())
+            .unwrap_or(&req.name);
+        let url = crate::skills::catalog::skill_download_url(catalog.registry_url(), download_key);
         crate::tools::builtin::skill_tools::fetch_skill_content(&url)
             .await
             .map_err(|e| (StatusCode::BAD_GATEWAY, e.to_string()))?

src/channels/web/static/app.js

@@ -3580,7 +3580,7 @@ function formatTimeAgo(epochMs) {
 }
 
 function installSkill(nameOrSlug, url, btn) {
-  var body = { name: nameOrSlug };
+  var body = { name: nameOrSlug, slug: nameOrSlug };
   if (url) body.url = url;
 
   apiFetch('/api/skills/install', {

src/channels/web/types.rs

@@ -569,6 +569,9 @@ pub struct SkillSearchResponse {
 #[derive(Debug, Deserialize)]
 pub struct SkillInstallRequest {
     pub name: String,
+    /// Registry slug (e.g. "owner/skill-name"). Preferred over `name` for
+    /// constructing the download URL when fetching from ClawHub.
+    pub slug: Option<String>,
     pub url: Option<String>,
     pub content: Option<String>,
 }