feat: update documentation structure and add deployment guide

README.md

@@ -12,7 +12,7 @@ Current stack:
 
 Project plan lives in [PLAN.md](PLAN.md).
 Task checklist lives in [.github/instructions/TODO.md](.github/instructions/TODO.md).
-Coolify deployment runbooks live in [DEPLOYMENT.md](DEPLOYMENT.md).
+Coolify deployment runbooks live in [docs/DEPLOYMENT.md](docs/DEPLOYMENT.md).
 
 ## Current Status
 
@@ -396,9 +396,9 @@ git.allucanget.biz/allucanget/arbitrade:latest
 
 ## Architecture Docs
 
-Implementation detail moved into arc42 docs:
+Implementation detail moved into docs:
 
-- [arc42 overview](docs/architecture/arc42.md) - system context, building blocks, runtime, deployment, quality goals, risks.
+- [architecture overview](docs/architecture/README.md) - system context, building blocks, runtime, deployment, quality goals, risks.
 - [current implementation snapshot](docs/architecture/current-implementation.md) - codebase state, active routes, backtesting, strategy flags, deployment flow.
 
 For navigation from README, use the docs above instead of this file for deep architecture detail.