feat: Add API endpoint for listing oneliners

This commit introduces a new API endpoint `/api/oneliners` that allows
authenticated users to retrieve a list of their recent oneliners.

The endpoint supports conditional GET requests using the `ETag` header
for efficient caching. It also allows specifying a time window for the
oneliners via the `hours` query parameter, with sensible defaults and
clamping.

The implementation includes:
- A new route handler `handle_oneliners`.
- A new type `OnelinerWatermark` for tracking user-specific timestamps.
- Logic for scanning user data directories, filtering by time, and
  handling deleted cases.
- Test cases to cover various scenarios, including caching, time
  windowing, and edge cases.

server/src/transcribe/worker.rs

@@ -2,12 +2,13 @@ use std::path::Path;
 use std::sync::Arc;
 use std::time::Duration;
 
+use time::OffsetDateTime;
 use tracing::{error, info, warn};
 
 use super::{ffmpeg, ollama, whisper, TranscribeReceiver};
 use crate::config::{Config, WhisperUserSettings};
 use crate::gazetteer::Gazetteer;
-use crate::{BusyGuard, WorkerBusy};
+use crate::{BusyGuard, OnelinerWatermark, WorkerBusy};
 
 const ONELINER_TIMEOUT: Duration = Duration::from_secs(60);
 
@@ -19,6 +20,7 @@ pub async fn run(
     client: reqwest::Client,
     worker_busy: WorkerBusy,
     vocab: Arc<Gazetteer>,
+    watermark: OnelinerWatermark,
 ) {
     info!("Transcription worker started");
     let timeout = Duration::from_secs(config.whisper_timeout_seconds);
@@ -88,7 +90,7 @@ pub async fn run(
         if let Some(case_dir) = audio_path.parent()
             && !has_pending_recordings(case_dir).await
         {
-            update_oneliner(case_dir, &client, &config, &vocab).await;
+            update_oneliner(case_dir, &job.user_slug, &client, &config, &vocab, &watermark).await;
         }
     }
 
@@ -127,9 +129,11 @@ async fn mark_failed(audio_path: &Path) {
 /// no-op — next transcript write retries.
 pub(crate) async fn update_oneliner(
     case_dir: &Path,
+    user_slug: &str,
     client: &reqwest::Client,
     config: &Config,
     vocab: &Gazetteer,
+    watermark: &OnelinerWatermark,
 ) {
     let path = case_dir.join("oneliner.txt");
 
@@ -154,6 +158,12 @@ pub(crate) async fn update_oneliner(
                 error!(path = %path.display(), error = %e, "writing oneliner failed");
             } else {
                 info!(path = %path.display(), chars = line.chars().count(), "Oneliner updated");
+                // Bump the per-user watermark so the next `/api/oneliners`
+                // poll sees a fresh ETag and fetches the new content.
+                watermark
+                    .write()
+                    .await
+                    .insert(user_slug.to_string(), OffsetDateTime::now_utc());
             }
         }
         Err(e) => {