fix(skill-loader): deterministic collision handling for skill names

- Separate directory and file entries, process directories first
- Use Map to deduplicate skills by name (first-wins)
- Directory skills (SKILL.md, {dir}.md) take precedence over file skills (*.md)
- Add test for collision scenario

Addresses Oracle P2 review feedback from PR #1254

src/features/opencode-skill-loader/loader.test.ts

@@ -516,5 +516,42 @@ Nested content.
         process.chdir(originalCwd)
       }
     })
+
+    it("prefers directory skill (SKILL.md) over file skill (*.md) on name collision", async () => {
+      // #given - both foo.md file AND foo/SKILL.md directory exist
+      // Directory skill should win (deterministic precedence: SKILL.md > {dir}.md > *.md)
+      const dirSkillDir = join(SKILLS_DIR, "collision-test")
+      mkdirSync(dirSkillDir, { recursive: true })
+      writeFileSync(join(dirSkillDir, "SKILL.md"), `---
+name: collision-test
+description: Directory-based skill (should win)
+---
+I am the directory skill.
+`)
+
+      // Also create a file with same base name at parent level
+      writeFileSync(join(SKILLS_DIR, "collision-test.md"), `---
+name: collision-test
+description: File-based skill (should lose)
+---
+I am the file skill.
+`)
+
+      // #when
+      const { discoverSkills } = await import("./loader")
+      const originalCwd = process.cwd()
+      process.chdir(TEST_DIR)
+
+      try {
+        const skills = await discoverSkills({ includeClaudeCodePaths: false })
+
+        // #then - only one skill should exist, and it should be the directory-based one
+        const matchingSkills = skills.filter(s => s.name === "collision-test")
+        expect(matchingSkills).toHaveLength(1)
+        expect(matchingSkills[0]?.definition.description).toContain("Directory-based skill")
+      } finally {
+        process.chdir(originalCwd)
+      }
+    })
   })
 })

src/features/opencode-skill-loader/loader.ts

@@ -140,53 +140,59 @@ async function loadSkillsFromDir(
   maxDepth: number = 2
 ): Promise<LoadedSkill[]> {
   const entries = await fs.readdir(skillsDir, { withFileTypes: true }).catch(() => [])
-  const skills: LoadedSkill[] = []
+  const skillMap = new Map<string, LoadedSkill>()
 
-  for (const entry of entries) {
-    if (entry.name.startsWith(".")) continue
+  const directories = entries.filter(e => !e.name.startsWith(".") && (e.isDirectory() || e.isSymbolicLink()))
+  const files = entries.filter(e => !e.name.startsWith(".") && !e.isDirectory() && !e.isSymbolicLink() && isMarkdownFile(e))
 
+  for (const entry of directories) {
     const entryPath = join(skillsDir, entry.name)
+    const resolvedPath = await resolveSymlinkAsync(entryPath)
+    const dirName = entry.name
 
-    if (entry.isDirectory() || entry.isSymbolicLink()) {
-      const resolvedPath = await resolveSymlinkAsync(entryPath)
-      const dirName = entry.name
-
-      const skillMdPath = join(resolvedPath, "SKILL.md")
-      try {
-        await fs.access(skillMdPath)
-        const skill = await loadSkillFromPath(skillMdPath, resolvedPath, dirName, scope, namePrefix)
-        if (skill) skills.push(skill)
-        continue
-      } catch {
+    const skillMdPath = join(resolvedPath, "SKILL.md")
+    try {
+      await fs.access(skillMdPath)
+      const skill = await loadSkillFromPath(skillMdPath, resolvedPath, dirName, scope, namePrefix)
+      if (skill && !skillMap.has(skill.name)) {
+        skillMap.set(skill.name, skill)
       }
-
-      const namedSkillMdPath = join(resolvedPath, `${dirName}.md`)
-      try {
-        await fs.access(namedSkillMdPath)
-        const skill = await loadSkillFromPath(namedSkillMdPath, resolvedPath, dirName, scope, namePrefix)
-        if (skill) skills.push(skill)
-        continue
-      } catch {
-      }
-
-      // Recurse into subdirectories if no skill found and within depth limit
-      if (depth < maxDepth) {
-        const newPrefix = namePrefix ? `${namePrefix}/${dirName}` : dirName
-        const nestedSkills = await loadSkillsFromDir(resolvedPath, scope, newPrefix, depth + 1, maxDepth)
-        skills.push(...nestedSkills)
-      }
-
       continue
+    } catch {
     }
 
-    if (isMarkdownFile(entry)) {
-      const baseName = basename(entry.name, ".md")
-      const skill = await loadSkillFromPath(entryPath, skillsDir, baseName, scope, namePrefix)
-      if (skill) skills.push(skill)
+    const namedSkillMdPath = join(resolvedPath, `${dirName}.md`)
+    try {
+      await fs.access(namedSkillMdPath)
+      const skill = await loadSkillFromPath(namedSkillMdPath, resolvedPath, dirName, scope, namePrefix)
+      if (skill && !skillMap.has(skill.name)) {
+        skillMap.set(skill.name, skill)
+      }
+      continue
+    } catch {
+    }
+
+    if (depth < maxDepth) {
+      const newPrefix = namePrefix ? `${namePrefix}/${dirName}` : dirName
+      const nestedSkills = await loadSkillsFromDir(resolvedPath, scope, newPrefix, depth + 1, maxDepth)
+      for (const nestedSkill of nestedSkills) {
+        if (!skillMap.has(nestedSkill.name)) {
+          skillMap.set(nestedSkill.name, nestedSkill)
+        }
+      }
     }
   }
 
-  return skills
+  for (const entry of files) {
+    const entryPath = join(skillsDir, entry.name)
+    const baseName = basename(entry.name, ".md")
+    const skill = await loadSkillFromPath(entryPath, skillsDir, baseName, scope, namePrefix)
+    if (skill && !skillMap.has(skill.name)) {
+      skillMap.set(skill.name, skill)
+    }
+  }
+
+  return Array.from(skillMap.values())
 }
 
 function skillsToRecord(skills: LoadedSkill[]): Record<string, CommandDefinition> {