refactor(opencode-skill-loader): split loader and merger into focused modules

Extract skill loading pipeline into single-responsibility modules:
- skill-discovery.ts, skill-directory-loader.ts, skill-deduplication.ts
- loaded-skill-from-path.ts, loaded-skill-template-extractor.ts
- skill-template-resolver.ts, skill-definition-record.ts
- git-master-template-injection.ts, allowed-tools-parser.ts
- skill-mcp-config.ts, skill-resolution-options.ts
- merger/ directory for skill merging logic

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

@@ -0,0 +1,45 @@
+import { promises as fs } from "fs"
+import { join } from "path"
+import yaml from "js-yaml"
+import type { SkillMcpConfig } from "../skill-mcp-manager/types"
+
+export function parseSkillMcpConfigFromFrontmatter(content: string): SkillMcpConfig | undefined {
+  const frontmatterMatch = content.match(/^---\r?\n([\s\S]*?)\r?\n---/)
+  if (!frontmatterMatch) return undefined
+
+  try {
+    const parsed = yaml.load(frontmatterMatch[1]) as Record<string, unknown>
+    if (parsed && typeof parsed === "object" && "mcp" in parsed && parsed.mcp) {
+      return parsed.mcp as SkillMcpConfig
+    }
+  } catch {
+    return undefined
+  }
+  return undefined
+}
+
+export async function loadMcpJsonFromDir(skillDir: string): Promise<SkillMcpConfig | undefined> {
+  const mcpJsonPath = join(skillDir, "mcp.json")
+
+  try {
+    const content = await fs.readFile(mcpJsonPath, "utf-8")
+    const parsed = JSON.parse(content) as Record<string, unknown>
+
+    if (parsed && typeof parsed === "object" && "mcpServers" in parsed && parsed.mcpServers) {
+      return parsed.mcpServers as SkillMcpConfig
+    }
+
+    if (parsed && typeof parsed === "object" && !("mcpServers" in parsed)) {
+      const hasCommandField = Object.values(parsed).some(
+        (value) => value && typeof value === "object" && "command" in (value as Record<string, unknown>)
+      )
+      if (hasCommandField) {
+        return parsed as SkillMcpConfig
+      }
+    }
+  } catch {
+    return undefined
+  }
+
+  return undefined
+}