feat: remove legacy OpenCode runtime

Cut product flows over to Coding/Pi and retain only the migration-owned v1 boundary. Promote supported native optional packages because electron-builder omitted pnpm transitive optional closure from the packaged ASAR.

electron/coding-projects/skill-registry.ts

@@ -1,4 +1,4 @@
-import { readFile } from 'node:fs/promises';
+import { readFile, readdir } from 'node:fs/promises';
 import path from 'node:path';
 import {
   BUNDLED_CODING_SKILL_IDS,
@@ -50,18 +50,40 @@ function selectedSkillIds(value: readonly string[]): Set<BundledCodingSkillId> {
   return selected;
 }
 
+async function listSkillEntries(
+  directory: string,
+  relative = '',
+): Promise<Array<{ path: string; type: 'file' | 'directory' }>> {
+  const entries = await readdir(path.join(directory, relative), { withFileTypes: true });
+  const result: Array<{ path: string; type: 'file' | 'directory' }> = [];
+  for (const entry of entries.sort((left, right) => left.name.localeCompare(right.name))) {
+    const entryPath = relative ? path.posix.join(relative, entry.name) : entry.name;
+    if (entry.isDirectory()) {
+      result.push({ path: entryPath, type: 'directory' });
+      result.push(...await listSkillEntries(directory, entryPath));
+    } else if (entry.isFile()) {
+      result.push({ path: entryPath, type: 'file' });
+    }
+  }
+  return result;
+}
+
 export async function listProductCodingSkills(
   bundledSkillsDir: string,
   selectedIds: readonly string[] = [],
 ): Promise<ProductCodingSkill[]> {
   const selected = selectedSkillIds(selectedIds);
   return await Promise.all(BUNDLED_CODING_SKILL_IDS.map(async (id) => {
-    const content = await readFile(path.join(bundledSkillsDir, id, 'SKILL.md'), 'utf8');
+    const location = path.join(bundledSkillsDir, id);
+    const content = await readFile(path.join(location, 'SKILL.md'), 'utf8');
     return {
       id,
       name: frontmatterScalar(content, 'name') ?? id,
       description: frontmatterScalar(content, 'description') ?? '',
       selected: selected.has(id),
+      location,
+      content,
+      entries: await listSkillEntries(location),
     };
   }));
 }