refactor(common): move package search into shared base

- Install nix-search-cli through common.nix
- Remove its development module entry and update documentation

README.md

@@ -103,7 +103,7 @@ language runtimes or Kubernetes/Terraform tooling. Android
 Studio remains on the ThinkPads as an existing IDE/workflow choice, but its
 bundled SDK is worth reviewing if moving fully to project-local tooling.
 
-For fast package discovery, the shared tools include `nix-search-cli`:
+For fast package discovery, `common.nix` installs `nix-search-cli` on every host:
 
 ```sh
 nix-search --channel=26.05 blender