fix: resolve symlinks in skill config source discovery and test paths

Use fs.realpath() in config-source-discovery to resolve symlinks before
loading skills, preventing duplicate/mismatched paths on systems where
tmpdir() returns a symlink (e.g., macOS /var → /private/var). Also adds
agents-config-dir utility for ~/.agents path resolution.

src/features/opencode-skill-loader/config-source-discovery.ts

@@ -53,26 +53,28 @@ async function loadSourcePath(options: {
   const stat = await fs.stat(absolutePath).catch(() => null)
   if (!stat) return []
 
+  const realBasePath = await fs.realpath(absolutePath).catch(() => absolutePath)
+
   if (stat.isFile()) {
-    if (!isMarkdownPath(absolutePath)) return []
+    if (!isMarkdownPath(realBasePath)) return []
     const loaded = await loadSkillFromPath({
-      skillPath: absolutePath,
-      resolvedPath: dirname(absolutePath),
-      defaultName: inferSkillNameFromFileName(absolutePath),
+      skillPath: realBasePath,
+      resolvedPath: dirname(realBasePath),
+      defaultName: inferSkillNameFromFileName(realBasePath),
       scope: "config",
     })
     if (!loaded) return []
-    return filterByGlob([loaded], dirname(absolutePath), options.globPattern)
+    return filterByGlob([loaded], dirname(realBasePath), options.globPattern)
   }
 
   if (!stat.isDirectory()) return []
 
   const directorySkills = await loadSkillsFromDir({
-    skillsDir: absolutePath,
+    skillsDir: realBasePath,
     scope: "config",
     maxDepth: options.recursive ? MAX_RECURSIVE_DEPTH : 0,
   })
-  return filterByGlob(directorySkills, absolutePath, options.globPattern)
+  return filterByGlob(directorySkills, realBasePath, options.globPattern)
 }
 
 export async function discoverConfigSourceSkills(options: {

src/shared/agents-config-dir.test.ts

@@ -0,0 +1,14 @@
+import { describe, test, expect } from "bun:test"
+import { getAgentsConfigDir } from "./agents-config-dir"
+
+describe("getAgentsConfigDir", () => {
+  test("returns path ending with .agents", () => {
+    // given agents config dir is requested
+
+    // when getAgentsConfigDir is called
+    const result = getAgentsConfigDir()
+
+    // then returns path ending with .agents
+    expect(result.endsWith(".agents")).toBe(true)
+  })
+})

src/shared/agents-config-dir.ts

@@ -0,0 +1,6 @@
+import { homedir } from "node:os"
+import { join } from "node:path"
+
+export function getAgentsConfigDir(): string {
+  return join(homedir(), ".agents")
+}

src/shared/file-utils.test.ts

@@ -1,10 +1,10 @@
 import { describe, it, expect, beforeAll, afterAll } from "bun:test"
-import { mkdirSync, writeFileSync, symlinkSync, rmSync } from "fs"
+import { mkdirSync, writeFileSync, symlinkSync, rmSync, realpathSync } from "fs"
 import { join } from "path"
 import { tmpdir } from "os"
 import { resolveSymlink, resolveSymlinkAsync, isSymbolicLink } from "./file-utils"
 
-const testDir = join(tmpdir(), "file-utils-test-" + Date.now())
+const testDir = join(realpathSync(tmpdir()), "file-utils-test-" + Date.now())
 
 // Create a directory structure that mimics the real-world scenario:
 //