remove all deploy-rs references from docs and config

- Update README, AGENTS.md, docs/index.md, docs/deployment/cd.md,
  docs/services/forgejo.md: replace deploy-rs with Comin everywhere
- Fix repo URL references (cryodev-server -> cryodev)
- Fix forgejo admin create command to use shell alias
- Rewrite cd.md for Comin-only deployment

README.md

@@ -6,8 +6,8 @@ Declarative NixOS infrastructure for the **cryodev** environment, managed with N
 
 ```bash
 # Clone repository
-git clone https://git.cryodev.xyz/steffen/cryodev-server.git
-cd cryodev-server
+git clone https://git.cryodev.xyz/steffen/cryodev.git
+cd cryodev
 
 # Check configuration
 nix flake check
@@ -20,7 +20,7 @@ nix build .#nixosConfigurations.cryodev-main.config.system.build.toplevel
 
 | Host | Architecture | Deployment | Description |
 |------|--------------|------------|-------------|
-| `cryodev-main` | x86_64 | Push (deploy-rs) | Main server |
+| `cryodev-main` | x86_64 | Pull (Comin) | Main server |
 | `cryodev-pi` | aarch64 | Pull (Comin) | Raspberry Pi client |
 
 ## Services
@@ -37,7 +37,7 @@ nix build .#nixosConfigurations.cryodev-main.config.system.build.toplevel
 
 SD card images for Raspberry Pi clients are **built automatically** on every push to `main`.
 
-Download from: [Releases](https://git.cryodev.xyz/steffen/cryodev-server/releases)
+Download from: [Releases](https://git.cryodev.xyz/steffen/cryodev/releases)
 
 ```bash
 # Flash to SD card