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.

experiments/src/lib.rs

@@ -17,13 +17,15 @@ use time::OffsetDateTime;
 use time::format_description::well_known::Iso8601;
 
 /// Generate a run identifier in the form
-/// `<UTC-ISO>_w-<wid>_l-<lid>_run<n>`. Used as the directory name under
+/// `<UTC-ISO>_l-<lid>_run<n>`. Used as the directory name under
 /// `case_<id>/runs/`.
-pub fn run_id(whisper_variant: &str, llm_variant: &str, run_index: u32) -> String {
+pub fn run_id(llm_variant: &str, run_index: u32) -> String {
     let now = OffsetDateTime::now_utc();
-    let stamp = now.format(&Iso8601::DEFAULT).unwrap_or_else(|_| "unknown".into());
+    let stamp = now
+        .format(&Iso8601::DEFAULT)
+        .unwrap_or_else(|_| "unknown".into());
     let safe_stamp = stamp.replace(':', "-").replace('.', "-");
-    format!("{safe_stamp}_w-{whisper_variant}_l-{llm_variant}_run{run_index}")
+    format!("{safe_stamp}_l-{llm_variant}_run{run_index}")
 }
 
 /// Read a prompt file. Returns empty string for an empty file (used as
@@ -61,8 +63,6 @@ pub struct RunMeta {
     pub run_id: String,
     pub created_at_utc: String,
     pub case: String,
-    pub whisper_variant: String,
-    pub whisper_hotwords_variant: Option<String>,
     pub llm_variant: String,
     pub whisper_url: String,
     pub llm_url: String,