Refactor gazetteer annotation format

The gazetteer now annotates text with `Canonical [?original]`. This
prioritizes the corrected term for the LLM while keeping the original
transcription as a fallback.

This change aligns the gazetteer's annotation strategy with the LLM's
prompt, which expects corrections to be marked for review. Previously,
the format was `original [?Canonical]`, which could lead to the LLM
using the potentially incorrect original term.

server/tests/analyze_test.rs

@@ -361,9 +361,9 @@ async fn analyze_worker_writes_document_via_wiremock() {
 }
 
 /// The analyze worker must route transcripts through the Gazetteer before
-/// sending them to the LLM. "Zerebrum" shares a Kölner-Phonetik code with
-/// the gazetteer entry "Cerebrum" (both encode to `87176`) and differs by
-/// exactly one character — so the annotation `Zerebrum [?Cerebrum]` must
+/// sending them to the LLM. "Zerebrum" differs from the gazetteer entry
+/// "Cerebrum" by exactly one character — so the annotation
+/// `Cerebrum [?Zerebrum]` (canonical anchor, original in bracket) must
 /// end up in the LLM request body.
 #[tokio::test]
 async fn analyze_worker_annotates_with_gazetteer() {
@@ -432,7 +432,7 @@ async fn analyze_worker_annotates_with_gazetteer() {
     assert_eq!(requests.len(), 1, "expected exactly one LLM request");
     let body = String::from_utf8(requests[0].body.clone()).unwrap();
     assert!(
-        body.contains("Zerebrum [?Cerebrum]"),
+        body.contains("Cerebrum [?Zerebrum]"),
         "expected gazetteer annotation in LLM request body, got:\n{body}",
     );