docs: rename project to declarative-runtime

Settle on a descriptive name that calls out the load-bearing concept
(declarative *runtime* state, distinct from build-time config). Updates:

  - flake.nix description.
  - top-level README title + tagline.
  - flake-input examples in services/forgejo/README.md and
    services/keycloak/README.md (input variable `declarative-runtime`,
    url `github:<org>/declarative-runtime`).

The git repo directory + the GitHub repo rename are deliberate side
effects to run when the new name lands externally; no in-tree code
references the old name.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: kmein

README.md

@@ -1,5 +1,6 @@
-# Declarative NixOS services via paired Terraform providers
+# declarative-runtime
 
+**Declarative NixOS service runtime config via paired OpenTofu providers.**
 Make NixOS services **more declaratively configurable** than upstream Nixpkgs
 modules allow, by pairing each service with its Terraform provider and
 reconciling the service's _runtime state_ once it is up.

flake.nix

@@ -1,5 +1,5 @@
 {
-  description = "Declarative NixOS service configuration via paired Terraform providers";
+  description = "declarative-runtime: declarative NixOS service runtime config via paired OpenTofu providers";
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

services/forgejo/README.md

@@ -20,17 +20,17 @@ step with the rest of your system.
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 
     # This repository.
-    declarative-services.url = "github:youruser/terraform-providers";
-    declarative-services.inputs.nixpkgs.follows = "nixpkgs";
+    declarative-runtime.url = "github:youruser/declarative-runtime";
+    declarative-runtime.inputs.nixpkgs.follows = "nixpkgs";
   };
 
   outputs =
-    { nixpkgs, declarative-services, ... }:
+    { nixpkgs, declarative-runtime, ... }:
     {
       nixosConfigurations.myhost = nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";
         modules = [
-          declarative-services.nixosModules.forgejo
+          declarative-runtime.nixosModules.forgejo
           ./host.nix
         ];
       };

services/keycloak/README.md

@@ -19,17 +19,17 @@ step with the rest of your system.
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 
-    declarative-services.url = "github:applicative-systems/terraform-providers";
-    declarative-services.inputs.nixpkgs.follows = "nixpkgs";
+    declarative-runtime.url = "github:applicative-systems/declarative-runtime";
+    declarative-runtime.inputs.nixpkgs.follows = "nixpkgs";
   };
 
   outputs =
-    { nixpkgs, declarative-services, ... }:
+    { nixpkgs, declarative-runtime, ... }:
     {
       nixosConfigurations.myhost = nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";
         modules = [
-          declarative-services.nixosModules.keycloak
+          declarative-runtime.nixosModules.keycloak
           ./host.nix
         ];
       };