feat: retool setup scripts as Debian 13-first (keep Fedora support)

- main-setup.sh: sudo/root preflight for fresh Debian installs; offer
  distro-agnostic 03-dotnet-setup.sh on all supported distros
- 01-package-install.sh: Debian package renames (bind9-dnsutils), batcat
  symlink, libvirt/QEMU stack; vendor repos for gh/terraform/kubectl +
  k9s/minikube binaries (not in Debian main); keep dnf path for Fedora
- 02-dev-tools-setup.sh: PEP 668 fallback for pynvim pip install
- 03-fedora-dotnet-setup.sh -> 03-dotnet-setup.sh: .NET SDK via official
  dotnet-install.sh (no MS repo), PostgreSQL + Podman/podman-docker
- zshrc: purge dead oh-my-zsh references (prompt is Oh-My-Posh)
- README: Debian 13 first-class; docs: record decisions + status

README.md

@@ -10,51 +10,51 @@ Run the main setup script to install software, configure development tools, and
 ./main-setup.sh
 ```
 
-The script will automatically detect your Linux distribution (Fedora, Ubuntu, Debian, etc.) and use the appropriate package manager.
+The script will automatically detect your Linux distribution (Debian 13 "trixie" is the primary target; Ubuntu and Fedora also work) and use the appropriate package manager (`apt` or `dnf`).
 
 ## What Gets Installed
 
-### Core Packages
-- Development tools: `git`, `gh`, `curl`, `wget`, `ripgrep`, `fd-find`
-- System utilities: `btop`, `fastfetch`, `zsh`, `flatpak`
-- Virtualization: `virt-manager`
+### Core Packages (distro packages)
+- Development tools: `git`, `curl`, `wget`, `ripgrep`, `fd-find`, `bat`, `eza`
+- System utilities: `btop`, `zsh`, `tmux`, `fzf`, `zoxide`, `flatpak`
+- Virtualization (KVM): `virt-manager` + libvirt/QEMU stack
 - Python: `python3`, `python3-pip`
-- Networking: `nmap`, `mtr`, `tcpdump`, `socat`, `whois`, `iperf3`, `traceroute`
-- Cloud / DevOps: `kubectl`, `k9s`, `minikube`, `terraform`, `helm`, `direnv`
-- HTTP: `curl`, `httpie`
+- Networking: `nmap`, `mtr`, `tcpdump`, `socat`, `whois`, `iperf3`, `traceroute`, `bind9-dnsutils`
+- HTTP: `httpie`
+- DevOps helpers: `ansible`, `direnv`, `jq`, `tldr`, `unzip`
 
-### Development Environment
-- **Neovim** (latest version from GitHub)
-- **Hack Nerd Font** for terminal
-- **Oh My Zsh** shell framework
-- **Starship** prompt
+### Upstream Tooling (installed by 01)
+`gh` (GitHub CLI), `terraform`, `kubectl`, `k9s` and `minikube` are **not packaged in Debian**, so `01-package-install.sh` adds the official vendor apt repositories (GitHub CLI, HashiCorp, `pkgs.k8s.io`) and installs `k9s`/`minikube` from upstream binaries. On Fedora these are a best-effort `dnf` install (usually COPR/manual).
+
+### Development Environment (02)
+- **Neovim** (latest from GitHub, installed to `/opt/nvim`)
+- **Hack Nerd Font** for terminals
+- **Go** toolchain (`/usr/local/go`)
 - **Rust** toolchain via rustup
+- **Oh-My-Posh** prompt (`~/.local/bin`)
+- **Helm**, **kubectx/kubens**, **stern**, **dive**, **trivy**, **AWS CLI v2**
 
-### Fedora-Specific (.NET Development)
-On Fedora systems, additional packages are installed:
-- **Visual Studio Code**
-- **.NET SDK** (with Microsoft repository)
+### .NET / Backend Services (03, optional)
+Distro-agnostic .NET development environment:
+- **.NET SDK** via the official `dotnet-install.sh` (no vendor repository needed)
 - **PostgreSQL** server and tools
-- **Docker** (moby-engine) with Docker Compose
+- **Podman** + `podman-compose` + `podman-docker` (Docker-CLI-compatible containers)
+- VS Code is installed as a **Flatpak** (`com.visualstudio.code`)
 
 ### Flatpak Applications
-- Bitwarden
-- Flatseal
-- Steam
-- ProtonUp-Qt
-- Rider
-- Veloren Airshipper
-- Visual Studio Code
-- VLC Media Player
+- Bolt, Bitwarden, Discord, Teams for Linux, Flatseal
+- Steam, ProtonUp-Qt (pupgui2), VLC
+- Visual Studio Code, Podman Desktop
+- Signal, Thunderbird
 
 ## Modular Architecture
 
 The setup is broken down into focused scripts:
 
 - `00-system-prep.sh` - System updates and Flathub setup
-- `01-package-install.sh` - Core packages and Flatpak apps
-- `02-dev-tools-setup.sh` - Development tools (Neovim, Go, Rust, Helm, kubectx, stern, dive, trivy, AWS CLI)
-- `03-fedora-dotnet-setup.sh` - Fedora-specific .NET environment
+- `01-package-install.sh` - Core packages, upstream tooling, and Flatpak apps
+- `02-dev-tools-setup.sh` - Development tools (Neovim, Go, Rust, Oh-My-Posh, Helm, kubectx, stern, dive, trivy, AWS CLI)
+- `03-dotnet-setup.sh` - .NET SDK + PostgreSQL + Podman (distro-agnostic)
 - `04-config-symlinks.sh` - Dotfile symlinking
 
 You can run individual scripts if you only need specific components.
@@ -97,14 +97,22 @@ After running the setup, remember to:
    ssh-keygen -t ed25519 -C ${USER}@$(hostname --fqdn)
    ```
 
-3. **Install Powerlevel10k gitstatus (if using):**
+3. **Set zsh as your login shell:**
    ```bash
-   ~/.oh-my-zsh/custom/themes/powerlevel10k/gitstatus/install -f
+   chsh -s /usr/bin/zsh
    ```
 
-4. **Log out and back in** for Docker group changes to take effect (Fedora)
+4. **Add yourself to virtualization groups** (log out/in afterward):
+   ```bash
+   sudo usermod -aG libvirt,kvm $USER
+   ```
 
-5. **Install VS Code extensions** (Fedora):
+5. **(Optional) enable the rootless Podman API socket:**
+   ```bash
+   systemctl --user enable --now podman.socket
+   ```
+
+6. **Install VS Code extensions:**
    - C# Dev Kit
    - GitLens
    - Prettier
@@ -112,9 +120,9 @@ After running the setup, remember to:
 
 ## Supported Distributions
 
-- **Fedora** (with full .NET development environment)
-- **Ubuntu/Debian** (core packages and development tools)
-- **Pop!_OS** (core packages and development tools)
+- **Debian 13 "trixie"** (primary target — full setup incl. upstream tooling, .NET, and backend services)
+- **Ubuntu / Pop!_OS** (apt; core + development tools)
+- **Fedora** (dnf; core + development tools, best-effort upstream tooling)
 
 ## Customization