Refactor: Remove unused Whisper variants

This commit removes the `whisper_variant` and `whisper_hotwords_variant`
fields from the `run_id` generation and the `print_meta_summary`
function.

These variants are no longer used as the project is shifting focus to
LLM-based generation. The `run_full_case.rs` example has also been
updated to reflect this change.

server/src/settings.rs

@@ -13,6 +13,8 @@ pub struct Settings {
     #[serde(default)]
     pub whisper: WhisperSettings,
     #[serde(default)]
+    pub canary: CanarySettings,
+    #[serde(default)]
     pub ollama: OllamaSettings,
     #[serde(default)]
     pub llm: LlmSettings,
@@ -72,6 +74,36 @@ fn default_whisper_timeout_seconds() -> u64 {
     120
 }
 
+/// Endpoint for the optional NeMo Canary container service. Active only
+/// when `ASR_BACKEND=canary` is set in `.env`. Both this block and
+/// `[whisper]` are always loaded; the worker reads only the active one.
+#[derive(Debug, Clone, Deserialize)]
+pub struct CanarySettings {
+    #[serde(default = "default_canary_url")]
+    pub url: String,
+    #[serde(default = "default_canary_timeout_seconds")]
+    pub timeout_seconds: u64,
+}
+
+impl Default for CanarySettings {
+    fn default() -> Self {
+        Self {
+            url: default_canary_url(),
+            timeout_seconds: default_canary_timeout_seconds(),
+        }
+    }
+}
+
+fn default_canary_url() -> String {
+    "http://localhost:9002".into()
+}
+/// Higher than Whisper's 120s default: Canary's buffered pipeline for
+/// audio >25s adds chunk-stitching cost (see docs/canary.md §4.1), so
+/// long dictations need a wider safety margin.
+fn default_canary_timeout_seconds() -> u64 {
+    180
+}
+
 #[derive(Debug, Clone, Deserialize)]
 pub struct OllamaSettings {
     #[serde(default = "default_ollama_url")]
@@ -180,6 +212,10 @@ mod tests {
 url = "http://h:1"
 timeout_seconds = 60
 
+[canary]
+url = "http://h:9"
+timeout_seconds = 240
+
 [ollama]
 url = "http://h:2"
 model = "x"
@@ -197,6 +233,8 @@ system_prompt = "p"
         .unwrap();
         assert_eq!(s.whisper.url, "http://h:1");
         assert_eq!(s.whisper.timeout_seconds, 60);
+        assert_eq!(s.canary.url, "http://h:9");
+        assert_eq!(s.canary.timeout_seconds, 240);
         assert_eq!(s.ollama.keep_alive, 5);
         assert_eq!(s.llm.api_key, "k");
         assert_eq!(s.llm.system_prompt, "p");
@@ -207,6 +245,8 @@ system_prompt = "p"
         let s: Settings = toml::from_str("").unwrap();
         assert_eq!(s.whisper.url, "http://localhost:10300");
         assert_eq!(s.whisper.timeout_seconds, 120);
+        assert_eq!(s.canary.url, "http://localhost:9002");
+        assert_eq!(s.canary.timeout_seconds, 180);
         assert_eq!(s.ollama.url, "http://localhost:11434");
         assert_eq!(s.ollama.model, "gemma3:4b");
         assert_eq!(s.llm.timeout_seconds, 180);