feat: Universal Agent API Bridge & Modular Skill Engine Overhaul

- Add Gitea/Vikunja API sync scripts to eliminate prompt-pollution.
- Move submodules to .agent/vendor for proper CLI encapsulation.
- Implement extract_skills.js to dynamically flatten 19 active skills.
- Translate CLI skill descriptions to Korean.
- Mask .env.agent in .gitignore ensuring true Zero-Pollution secure template.

.gitmodules

@@ -1,5 +1,5 @@
 [submodule ".agent/skills/superpowers"]
-	path = .agent/skills/superpowers
+	path = .agent/vendor/superpowers
 	url = https://github.com/obra/superpowers.git
 	branch = main
 [submodule ".agent/knowledge/everything_claude"]
@@ -11,7 +11,7 @@
 	url = https://github.com/hesreallyhim/awesome-claude-code.git
 	branch = main
 [submodule ".agent/skills/obsidian-skills"]
-	path = .agent/skills/obsidian-skills
+	path = .agent/vendor/obsidian-skills
 	url = https://github.com/kepano/obsidian-skills.git
 	branch = main
 [submodule ".agent/services/claude-mem"]
@@ -23,10 +23,10 @@
 	url = https://github.com/modelcontextprotocol/servers.git
 	branch = main
 [submodule ".agent/skills/browser_use"]
-	path = .agent/skills/browser_use
+	path = .agent/vendor/browser_use
 	url = https://github.com/browser-use/browser-use.git
 	branch = main
 [submodule ".agent/skills/mini-swe"]
-	path = .agent/skills/mini-swe
+	path = .agent/vendor/mini-swe
 	url = https://github.com/swe-agent/swe-agent.git
 	branch = main