chore: quantlab-agent 프로젝트 초기 설정

agent_guide 템플릿 기반으로 프로젝트 구조 설정.
Gitea(quantlab-agent), Vikunja(project #15) 연동 완료.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.agent/skills/gsd-remove-workspace/SKILL.md

@@ -0,0 +1,22 @@
+---
+name: gsd-remove-workspace
+description: Remove a GSD workspace and clean up worktrees
+---
+
+<context>
+**Arguments:**
+- `<workspace-name>` (required) — Name of the workspace to remove
+</context>
+
+<objective>
+Remove a workspace directory after confirmation. For worktree strategy, runs `git worktree remove` for each member repo first. Refuses if any repo has uncommitted changes.
+</objective>
+
+<execution_context>
+@.agent/get-shit-done/workflows/remove-workspace.md
+@.agent/get-shit-done/references/ui-brand.md
+</execution_context>
+
+<process>
+Execute the remove-workspace workflow from @.agent/get-shit-done/workflows/remove-workspace.md end-to-end.
+</process>