docs(openspec): add OpenSpec changes for FN-005, FN-006, FN-008, FN-009, FN-010

- Add frontend-foundation change (FN-005) with 46 tasks
- Add deployment-config change (FN-006) with 27 tasks
- Add runfusion-poc/opencode-poc change (FN-008) with 25 tasks
- Add config-secrets change (FN-009) with 31 tasks
- Add codeserver-spawn change (FN-010) with 38 tasks
- Include project specsheet and configuration
- Archive completed deployment-config change

openspec/config.yaml

@@ -0,0 +1,48 @@
+schema: spec-driven
+
+# Project context - shown to AI when creating artifacts
+context: |
+  Tech stack:
+    - Frontend: React 19 + Vite 6 + TypeScript 5
+    - Backend: FastAPI + SQLAlchemy 2.0 (async) + Pydantic v2 + Alembic
+    - Database: PostgreSQL 17
+    - Auth: Authentik OIDC (planned)
+    - Runtime: Docker Compose (Portainer-managed production)
+    - Routing: Traefik subdomain-based
+    - Monorepo: pnpm workspace
+  
+  Conventions:
+    - Task IDs follow FN-XXX pattern (e.g., FN-002, FN-003)
+    - Conventional commits with scope: feat(FN-XXX), fix(FN-XXX), docs(FN-XXX)
+    - Backend models in apps/api/app/models/
+    - Backend routers in apps/api/app/routers/
+    - Frontend code in apps/web/src/
+    - Tests: Vitest (frontend), pytest (backend)
+    - Documentation in docs/ folder (architecture.md, mvp-scope.md, etc.)
+  
+  Domain knowledge:
+    - Headquarter: hosted workspace + tool-orchestration platform
+    - Users create projects, connect Git repos, spawn containerized tools
+    - Built-in tools: OpenCode and code-server
+    - Each tool instance gets HTTPS subdomain via Traefik
+    - Manifest-driven tool registry with JSON schema
+    - Provider-abstracted Git (GitHub, GitLab, Gitea, Forgejo)
+    - Per-repository SSH key generation (Ed25519)
+    - Encrypted secret storage (Fernet)
+    - Config storage at global/user/project/tool-instance scopes
+
+# Per-artifact rules
+rules:
+  proposal:
+    - Always reference the task ID (FN-XXX) in the proposal
+    - Include dependency on previous FN tasks if applicable
+    - Reference docs/mvp-scope.md for scope boundaries
+  design:
+    - Follow existing patterns in apps/api/app/ and apps/web/src/
+    - Reference architecture.md for system design decisions
+    - Include database schema changes if applicable
+  tasks:
+    - Break tasks into implementation steps (Step 1, Step 2, etc.)
+    - Include test verification step
+    - Include documentation update step
+    - Reference specific files that need modification