Add Phase 3 tutorials with audience targeting (#94)

## Summary
- Create tutorials directory structure with index page
- Add 5 main tutorials targeting different audiences:
  - **what-is-blumeops** (Reader, AI) - High-level orientation
  - **exploring-the-docs** (All) - Navigation guide
  - **ai-assistance-guide** (AI, Owner) - Context for AI-assisted operations
  - **contributing** (Contributor) - First contribution workflow
  - **replicating-blumeops** (Replicator) - Overview for building similar setup
- Add 4 replication sub-tutorials:
  - tailscale-setup, kubernetes-bootstrap, argocd-config, observability-stack
- Update README.md to mark Phase 3 complete
- Add changelog fragment

Each tutorial explicitly identifies its target audiences and links to reference material rather than re-explaining concepts.

## Deployment and Testing
- [x] All pre-commit hooks pass (doc-links validates wiki links)
- [ ] Build docs via workflow to verify rendering
- [ ] Review content for accuracy

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/94

docs/tutorials/replication/core-services.md

@@ -0,0 +1,113 @@
+---
+title: core-services
+tags:
+  - tutorials
+  - replication
+  - forgejo
+---
+
+# Core Services Setup
+
+> **Audiences:** Replicator
+
+This tutorial walks through setting up the foundational services that your GitOps infrastructure depends on: a git forge and optionally a container registry.
+
+## Why Core Services First?
+
+Before Kubernetes and ArgoCD, you need somewhere to store your infrastructure definitions. [[forgejo]] provides:
+- Git hosting for your GitOps repository
+- CI/CD workflows for building and deploying
+- A web interface for code review and PRs
+
+The [[zot]] container registry is optional but useful for hosting your own container images.
+
+## Step 1: Install Forgejo
+
+Forgejo runs directly on your server (not in Kubernetes) because Kubernetes depends on it.
+
+### Using Ansible (BlumeOps Approach)
+
+BlumeOps manages Forgejo via an Ansible role. See [[reference/ansible/roles | Ansible Roles]].
+
+### Manual Installation
+
+1. Download Forgejo from [forgejo.org](https://forgejo.org/download/)
+2. Create a service user and directories
+3. Configure with `app.ini`
+4. Set up as a system service
+
+Key configuration points:
+- SSH on a non-standard port (e.g., 2222) to avoid conflicts
+- Database (SQLite works fine for personal use)
+- Domain and URL settings for your Tailscale hostname
+
+## Step 2: Configure SSH Access
+
+Set up SSH for git operations:
+
+```bash
+# Add your SSH key to Forgejo via the web UI
+# Then test access:
+ssh -T git@your-server.tailnet.ts.net -p 2222
+```
+
+## Step 3: Create Your GitOps Repository
+
+1. Create a new repository in Forgejo (e.g., `infrastructure` or `homelab`)
+2. Initialize the standard directory structure:
+
+```
+your-repo/
+├── ansible/           # Host configuration
+│   ├── playbooks/
+│   └── roles/
+├── argocd/            # Kubernetes GitOps
+│   ├── apps/          # ArgoCD Applications
+│   └── manifests/     # K8s manifests per service
+├── pulumi/            # IaC for Tailscale, DNS
+└── docs/              # Documentation
+```
+
+3. Push your initial commit
+
+## Step 4: Set Up CI/CD Runner (Optional)
+
+Forgejo Actions runs workflows defined in `.forgejo/workflows/`. To use it:
+
+1. Register a runner on your server
+2. Configure runner to access your build tools
+3. Create workflow files for builds and deployments
+
+BlumeOps runs a Forgejo runner in Kubernetes - see [[forgejo]] for details.
+
+## Step 5: Container Registry (Optional)
+
+If you'll build custom container images, set up [[zot]]:
+
+1. Install Zot on your server
+2. Configure authentication
+3. Set up TLS (via Caddy or similar)
+
+For getting started, you can skip this and use public registries.
+
+## What You Now Have
+
+- Git hosting for infrastructure code
+- SSH access for git operations
+- Foundation for CI/CD workflows
+- Optionally, a private container registry
+
+## Next Steps
+
+- [[tutorials/replication/kubernetes-bootstrap | Bootstrap Kubernetes]] - Now that you have a git repo, set up your cluster
+- Configure Forgejo webhooks for ArgoCD (after ArgoCD is running)
+
+## BlumeOps Specifics
+
+BlumeOps' Forgejo setup includes:
+- Ansible role for installation and updates
+- SSH on port 2222, proxied via Caddy
+- Integration with ArgoCD via deploy keys
+- Forgejo runner in Kubernetes for CI/CD
+
+See [[forgejo]] and [[zot]] for full details.