docs: update all documentation for OpenCode and deployment

- Update architecture.md with spawn service and auth proxy sections
- Update deployment.md with production stack details
- Update development.md with spawn workflow documentation
- Update mvp-scope.md, project-brief.md, tool-manifest-spec.md
- Update conversation-handoff.md with current status
- Replace all RunFusion references with OpenCode

docs/mvp-scope.md

@@ -7,7 +7,7 @@
 
 ## 1. Product Vision
 
-Headquarter is a hosted workspace and tool-orchestration platform for developers who want self-hosted control over their development environments. It gives authenticated users a single dashboard to create Git-backed projects, connect repositories from any provider, and spawn containerized tools—starting with RunFusion and code-server—on demand, each accessible via its own HTTPS subdomain. Headquarter is for individual developers and small teams who outgrow cloud IDEs but do not want to build their own orchestration layer from scratch.
+Headquarter is a hosted workspace and tool-orchestration platform for developers who want self-hosted control over their development environments. It gives authenticated users a single dashboard to create Git-backed projects, connect repositories from any provider, and spawn containerized tools—starting with OpenCode and code-server—on demand, each accessible via its own HTTPS subdomain. Headquarter is for individual developers and small teams who outgrow cloud IDEs but do not want to build their own orchestration layer from scratch.
 
 ---
 
@@ -36,7 +36,7 @@ An MVP user can complete the following end-to-end flows without assistance:
 - The public key is displayed to the user for manual registration at the provider, or registered automatically via the provider adapter when available.
 
 ### 2.5 Spawn a Tool Instance
-- User navigates to "Tools" and selects a tool (RunFusion or code-server).
+- User navigates to "Tools" and selects a tool (OpenCode or code-server).
 - User chooses a project and optional config overrides.
 - The backend generates a Docker Compose service definition, Traefik labels, and starts the container.
 - The tool instance receives workspace mounts, config mounts, and secret injection.
@@ -70,7 +70,7 @@ An MVP user can complete the following end-to-end flows without assistance:
 - **Project management** (CRUD, ownership-based)
 - **Repository connections** with provider-agnostic Git URL storage
 - **Per-repository SSH key generation** (Ed25519) with encrypted private-key storage
-- **Tool registry** with manifest-driven definitions for RunFusion and code-server
+- **Tool registry** with manifest-driven definitions for OpenCode and code-server
 - **Tool instance spawning** via Docker Compose with Traefik subdomain routing
 - **Tool instance lifecycle** (start, stop, health checks, status tracking)
 - **Persistent config storage** at global, user, project, and tool-instance scopes
@@ -111,12 +111,12 @@ Slices are ordered by dependency. Each slice corresponds to a task on the Fusion
 | 2 | **FN-019** | Architecture & Specification | Enhanced `docs/architecture.md`, `docs/mvp-scope.md`, doc validation tests |
 | 3 | **FN-004** | Backend Foundation | Domain models, Alembic migrations, auth boundaries, secret encryption, API routers |
 | 4 | **FN-005** | Frontend Foundation | Auth shell, navigation, placeholder pages, API client, config layer |
-| 5 | **FN-003** | Tool Registry | Manifest schema, in-memory registry, built-in RunFusion/code-server manifests, FastAPI routes |
+| 5 | **FN-003** | Tool Registry | Manifest schema, in-memory registry, built-in OpenCode/code-server manifests, FastAPI routes |
 | 6 | **FN-006** | Deployment Config | Traefik label generator, production Compose stacks, Portainer stack definition |
 | 7 | **FN-011** | Git Provider Model | Provider abstraction, SSH key lifecycle, credential models, repository connection |
 | 8 | **FN-009** | Config & Secrets | Encrypted storage, runtime injection, frontend config/secrets UI |
 | 9 | **FN-010** | code-server Spawn | code-server manifest, spawn flow, runtime integration, auth layer |
-| 10 | **FN-008** | RunFusion POC | Executable environment, Node/npm runtime, health reporting |
+| 10 | **FN-008** | OpenCode POC | AI-powered terminal environment, web interface, health reporting |
 
 **Dependency notes:**
 - FN-004 and FN-005 can proceed in parallel once FN-019 is complete.
@@ -139,7 +139,7 @@ FN-002 (Scaffold)
    │                              ├──> FN-003 (Tool Registry)
    │                              │       │
    │                              │       ├──> FN-010 (code-server Spawn)
-   │                              │       └──> FN-008 (RunFusion POC)
+   │                              │       └──> FN-008 (OpenCode POC)
    │                              │
    │                              ├──> FN-011 (Git Provider)
    │                              │