rename: kafka → samsa

Full project rename from kafka to samsa (after Gregor Samsa, who
woke one morning from uneasy dreams to find himself transformed).

- Module: github.com/metamorphosis-dev/kafka → samsa
- Binary: cmd/kafka/ → cmd/samsa/
- CSS: kafka.css → samsa.css
- UI: all 'kafka' product names, titles, localStorage keys → samsa
- localStorage keys: kafka-theme → samsa-theme, kafka-engines → samsa-engines
- OpenSearch: ShortName, LongName, description, URLs updated
- AGPL headers: 'kafka' → 'samsa'
- Docs, configs, examples updated
- Cache key prefix: kafka: → samsa:

README.md

@@ -1,4 +1,4 @@
-# kafka
+# samsa
 
 A privacy-respecting, open metasearch engine written in Go. SearXNG-compatible API with an HTML frontend, designed to be fast, lightweight, and deployable anywhere.
 
@@ -12,7 +12,7 @@ A privacy-respecting, open metasearch engine written in Go. SearXNG-compatible A
 - **Valkey cache** — optional Redis-compatible caching with configurable TTL
 - **Rate limiting** — three layers: per-IP, burst, and global (all disabled by default)
 - **CORS** — configurable origins for browser-based clients
-- **OpenSearch** — browsers can add kafka as a search engine from the address bar
+- **OpenSearch** — browsers can add samsa as a search engine from the address bar
 - **Graceful degradation** — individual engine failures don't kill the whole search
 - **Docker** — multi-stage build, ~20MB runtime image
 - **NixOS** — native NixOS module with systemd service
@@ -23,9 +23,9 @@ A privacy-respecting, open metasearch engine written in Go. SearXNG-compatible A
 
 ```bash
 git clone https://git.ashisgreat.xyz/penal-colony/gosearch.git
-cd kafka
-go build ./cmd/kafka
-./kafka -config config.toml
+cd samsa
+go build ./cmd/samsa
+./samsa -config config.toml
 ```
 
 ### Docker Compose
@@ -41,28 +41,28 @@ docker compose up -d
 Add to your flake inputs:
 
 ```nix
-inputs.kafka.url = "git+https://git.ashisgreat.xyz/penal-colony/gosearch.git";
+inputs.samsa.url = "git+https://git.ashisgreat.xyz/penal-colony/gosearch.git";
 ```
 
 Enable in your configuration:
 
 ```nix
-imports = [ inputs.kafka.nixosModules.default ];
+imports = [ inputs.samsa.nixosModules.default ];
 
-services.kafka = {
+services.samsa = {
   enable = true;
   openFirewall = true;
   baseUrl = "https://search.example.com";
-  # config = "/etc/kafka/config.toml";  # default
+  # config = "/etc/samsa/config.toml";  # default
 };
 ```
 
 Write your config:
 
 ```bash
-sudo mkdir -p /etc/kafka
-sudo cp config.example.toml /etc/kafka/config.toml
-sudo $EDITOR /etc/kafka/config.toml
+sudo mkdir -p /etc/samsa
+sudo cp config.example.toml /etc/samsa/config.toml
+sudo $EDITOR /etc/samsa/config.toml
 ```
 
 Deploy:
@@ -76,7 +76,7 @@ sudo nixos-rebuild switch --flake .#
 ```bash
 nix develop
 go test ./...
-go run ./cmd/kafka -config config.toml
+go run ./cmd/samsa -config config.toml
 ```
 
 ## Endpoints