refactor(desktop): drop dead revision helper superseded by /revision endpoint

The current_workflow_revision helper in desktop trigger_workflow was
referenced only from #[cfg(test)] workflows_tests.rs after the exact
signed-revision binding moved server-side behind the authenticated
/workflows/{id}/revision endpoint, leaving a dead-code lint risk in
non-test desktop builds. Remove the helper and its unit test.

Co-authored-by: Wakko <0999168a3b1a4dabdf398cf43ba2893bb29b74dc06d0b31c2d3b51dbebea1612@buzz.block.builderlab.xyz>
Signed-off-by: Logan Johnson <loganj@squareup.com>

desktop/src-tauri/src/commands/workflows.rs

@@ -377,13 +377,6 @@ pub async fn deny_approval(
 
 // ── Helpers (pure, unit-tested in workflows_tests.rs) ─────────────────────────
 
-fn current_workflow_revision(events: &[nostr::Event]) -> Result<String, String> {
-    events
-        .first()
-        .map(|event| event.id.to_hex())
-        .ok_or_else(|| "workflow not found".to_string())
-}
-
 fn trigger_wire_from_message(
     workflow_id: String,
     message: &str,

desktop/src-tauri/src/commands/workflows_tests.rs

@@ -273,20 +273,6 @@ fn channel_workflow_filters_accepts_empty_input() {
     );
 }
 
-#[test]
-fn trigger_command_uses_current_definition_event_id() {
-    let event = wf_event(WF, CHAN, YAML);
-    let revision = event.id.to_hex();
-    assert_eq!(
-        current_workflow_revision(std::slice::from_ref(&event)).as_deref(),
-        Ok(revision.as_str())
-    );
-    assert_eq!(
-        current_workflow_revision(&[]).expect_err("empty result must fail"),
-        "workflow not found"
-    );
-}
-
 #[test]
 fn trigger_response_uses_persisted_run_id_contract() {
     let wire = trigger_wire_from_message(