docs: [#31] clarify repository transition strategy

- Add clear repository transition plan in docs/redesign/README.md
- Current repo becomes 'torrust-tracker-demo-poc' (archived)
- New repo 'torrust-tracker-installer' for implementation
- Documentation transfer after Phase 4 completion
- Separate specification (Phases 0-4) from implementation (Phases 5-7)
- Update phase flow to show 8-phase complete process

Author: josecelano

docs/redesign/README.md

@@ -6,6 +6,36 @@
 These docs (Issue **#31**) explain where we are going and why. Keep it light, clear and
 useful for future contributors.
 
+## 🔄 Repository Transition Strategy
+
+This repository serves as the **specification and design phase** for the new production  
+system. Here's the complete transition plan:
+
+### 1. **Current Repository (`torrust-tracker-demo`)**
+
+- **Final Status**: Will be archived as `torrust-tracker-demo-poc`
+- **Purpose**: Historical reference and complete specification for new system
+- **Contains**: Complete documentation through Phase 4 (Goals → Requirements → Analysis → Design → Planning)
+- **Role**: Blueprint and specification source for the new implementation
+
+### 2. **New Repository (`torrust-tracker-installer`)**
+
+- **Purpose**: Production-grade deployment system implementation
+- **Foundation**: Copy of this redesign documentation as starting point
+- **Implementation Phases**:
+  - **Phase 5**: Implementation 🔨
+  - **Phase 6**: Testing & Validation 🧪
+  - **Phase 7**: Migration & Deployment 🚀
+
+### 3. **Documentation Handover**
+
+- **What Transfers**: All `docs/redesign/` content copied to new repository
+- **What Stays**: PoC code and configuration (for historical reference)
+- **Timing**: After Phase 4 (Planning) completion in this repository
+
+This approach separates **specification** (this repo) from **implementation** (new repo),  
+ensuring clean separation of concerns and clear project boundaries.
+
 ## What You Can Do Now
 
 | You want to…                                      | Allowed? | How                                             |
@@ -38,14 +68,22 @@ After a quick review we move to Phase 2 (measure current behaviour: performance,
 | `phase4-planning/`     | Milestones & rollout plan                  |
 | `community-input/`     | Collected suggestions & feedback           |
 
-## Simple 5-Phase Flow
+## Simple 8-Phase Flow
+
+**Specification & Design Phases** (in this repository):
 
 0. Goals & scope (what we're trying to achieve)
 1. Requirements (what matters technically)
 2. Analyse current PoC (truth vs assumptions)
 3. Design new solution
 4. Plan build & migration
 
+**Implementation Phases** (in new `torrust-tracker-installer` repository):
+
+5. Implementation (build the new system)
+6. Testing & validation (comprehensive testing)
+7. Migration & deployment (production rollout)
+
 ## Next Up (Short List)
 
 | Item                                                | Phase | Status         |