fix(skills): expand tilde config source paths

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

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

@@ -1,5 +1,6 @@
 import { afterEach, beforeEach, describe, expect, it } from "bun:test"
 import { mkdirSync, rmSync, writeFileSync } from "fs"
+import { homedir } from "os"
 import { join } from "path"
 import { homedir, tmpdir } from "os"
 import { SkillsConfigSchema } from "../../config/schema/skills"
@@ -101,4 +102,29 @@ describe("config source discovery", () => {
     // then
     expect(normalized).toBe("keep/nested/SKILL.md")
   })
+
+  it("loads skills from ~/ sources paths", async () => {
+    // given
+    const homeTestDir = join(homedir(), `.omo-config-source-${Date.now()}`)
+    const sourceDir = join(homeTestDir, "custom-skills")
+    writeSkill(join(sourceDir, "tilde-skill"), "tilde-skill", "Loaded from tilde source")
+    const config = SkillsConfigSchema.parse({
+      sources: [{ path: `${homeTestDir.replace(homedir(), "~")}/custom-skills`, recursive: true }],
+    })
+
+    try {
+      // when
+      const skills = await discoverConfigSourceSkills({
+        config,
+        configDir: join(TEST_DIR, "config"),
+      })
+
+      // then
+      const tildeSkill = skills.find((skill) => skill.name === "tilde-skill")
+      expect(tildeSkill).toBeDefined()
+      expect(tildeSkill?.definition.description).toContain("Loaded from tilde source")
+    } finally {
+      rmSync(homeTestDir, { recursive: true, force: true })
+    }
+  })
 })

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

@@ -1,6 +1,7 @@
 import { promises as fs } from "fs"
 import { homedir } from "os"
 import { dirname, extname, isAbsolute, join, relative } from "path"
+import { homedir } from "os"
 import picomatch from "picomatch"
 import type { SkillsConfig } from "../../config/schema"
 import { normalizeSkillsConfig } from "./merger/skills-config-normalizer"