Schedule pickers, and target progress at one row

"Check feeds every" becomes a number plus a unit dropdown in both global
and per-feed settings; parse_interval gained weeks to back it. The
per-feed dropdown can select the global default, clearing the override.

Fixes progress painting every pending row: the event carried no enclosure
id, so the handler had nothing to target and set the width on all of them.
Adding a feed looked like it was downloading everything. Progress,
DownloadDone and DownloadError now carry the enclosure id.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AdXho5tTkjFLeUXKbEjKBh

src/web.rs

@@ -154,6 +154,8 @@ struct FeedRow {
     auto_download: bool,
     max_new_per_check: Option<usize>,
     schedule: Option<String>,
+    /// The feed's own override in minutes, so the UI need not re-parse the string.
+    schedule_mins: Option<u64>,
     /// Effective schedule in minutes, after the global default and the feed's <ttl>.
     every_mins: u64,
     last_checked: Option<i64>,
@@ -181,6 +183,10 @@ async fn feeds(State(state): State<WebState>) -> Result<Json<Vec<FeedRow>>, ApiE
             auto_download: feed.auto_download,
             max_new_per_check: feed.max_new_per_check,
             schedule: feed.schedule.clone(),
+            schedule_mins: feed
+                .schedule
+                .as_deref()
+                .and_then(crate::config::parse_interval),
             every_mins: crate::due_after(&cfg, feed, st.ttl_mins) / 60,
             last_checked: s.last_checked,
             next_check: s