{"messages":[{"content":"You are a constitutional council ranking individual git commits for ownership allocation.\n\nCompare these two commits. Decide which contributed more lasting value to the project.\n\nJudge substance, not spectacle:\n- Prefer correct, lasting design and real bugfixes over churn, formatting, renames, or generated noise.\n- Prefer clarity and necessity over sheer line count. A small precise change can beat a large diffuse one.\n- Do not favor a side merely because its patch is longer or noisier.\n- Weight what the change does for the project, not the contributor's name.\n\nReturn ONLY a JSON object: {\"winner\": \"A\" or \"B\", \"ratio\": \"N:M\", \"explanation\": \"...\"}\nThe explanation must cite concrete differences in the patches (1-3 sentences).\n\nSide A — contributor: tommy-mor\nSide A — commit message:\n[07715165] nice\n\nSide A — unified diff (full patch):\ndiff --git a/server/src/api/ui_html.rs b/server/src/api/ui_html.rs\nindex c3c62a76f424010d77a6090c84dd0b82098f573e..da2536112faea313352624cf2ce0ddd0ab3377c1 100644\n--- a/server/src/api/ui_html.rs\n+++ b/server/src/api/ui_html.rs\n@@ -6,7 +6,7 @@ use axum::{\n use std::collections::HashMap;\n \n use crate::{\n-    html::{demo_counter_panel, js_string_literal, ranking_panel, JsBuilder},\n+    html::{js_string_literal, ranking_panel, JsBuilder},\n     parser::parse_reddit_url,\n     parser_render::parser_panel_morph,\n     state::AppState,\n@@ -35,13 +35,6 @@ pub async fn post_ui_html(\n     };\n \n     match action {\n-        HtmlUiAction::BumpDemoCounter => {\n-            let count = state.bump_demo_counter().await;\n-            let panel = demo_counter_panel(count, state.event_log.path().to_string_lossy().as_ref());\n-            JsBuilder::new()\n-                .morph_selector(\"#demo-counter-panel\", panel)\n-                .into_response()\n-        }\n         HtmlUiAction::RecordVote {\n             a,\n             b,\n@@ -54,8 +47,8 @@ pub async fn post_ui_html(\n             {\n                 return ui_js_warn(&e).into_response();\n             }\n-            let mut group = state.group.write().await;\n-            let panel = ranking_panel(&mut group);\n+            let group = state.group.read().await;\n+            let panel = ranking_panel(&group);\n             JsBuilder::new()\n                 .morph_selector(\"#ranking-panel\", panel)\n                 .into_response()\n@@ -87,20 +80,6 @@ mod tests {\n         assert!(matches!(err, HtmlUiParseError::MissingRpc));\n     }\n \n-    #[test]\n-    fn bump_action_deserializes() {\n-        let template = serde_json::json!({ \"action\": \"bump_demo_counter\" });\n-        let mut form = HashMap::new();\n-        form.insert(\n-            UI_RPC_FIELD.to_string(),\n-            serde_json::to_string(&template).unwrap(),\n-        );\n-        assert_eq!(\n-            parse_html_ui_from_form(&form).unwrap(),\n-            HtmlUiAction::BumpDemoCounter\n-        );\n-    }\n-\n     #[test]\n     fn record_vote_action_deserializes() {\n         let template = serde_json::json!({\ndiff --git a/server/src/events.rs b/server/src/events.rs\nindex b969242534e184d4f0a689543a479670b08a18df..eff80aef0257f706d2341f666e63d6a3d921bf6e 100644\n--- a/server/src/events.rs\n+++ b/server/src/events.rs\n@@ -5,8 +5,6 @@ use serde::{Deserialize, Serialize};\n pub enum Event {\n     /// Page view recorded (path → counter in views.json).\n     ViewRecorded { path: String, ts: i64 },\n-    /// Demo counter bump from `POST /ui` (persisted in the single JSONL log).\n-    DemoCounterBumped { ts: i64, value: u64 },\n     /// Pairwise comparison vote (replayed into [`crate::reducer::GroupState`] on boot).\n     VoteRecorded {\n         ts: i64,\ndiff --git a/server/src/html/mod.rs b/server/src/html/mod.rs\nindex 5b1d0b5a887d89e7e80796aa7a6c8ed5baaf2782..d69ed962b5c8625bc83c933b1825f2cc1d0868e2 100644\n--- a/server/src/html/mod.rs\n+++ b/server/src/html/mod.rs\n@@ -13,7 +13,7 @@ use crate::{\n     form_template::template_json_compact,\n     parser_action::ParserAction,\n     parser_render::parser_panel,\n-    ranking::ranked_items,\n+    ranking::ranked_items_cached,\n     reducer::GroupState,\n     state::AppState,\n     ui_action::UI_RPC_FIELD,\n@@ -199,10 +199,8 @@ fn layout(title: &str, body: Markup, views: u64, theme: &str, theme_next: &str)\n     }\n }\n \n-pub fn ranking_panel(group: &mut GroupState) -> Markup {\n-    const MAX_ITERS: usize = 10_000;\n-    const TOL: f64 = 1e-8;\n-    let items = ranked_items(group, MAX_ITERS, TOL);\n+pub fn ranking_panel(group: &GroupState) -> Markup {\n+    let items = ranked_items_cached(group);\n     html! {\n         section id=\"ranking-panel\" class=\"demo-panel\" {\n             h2 { \"Ranking\" }\n@@ -260,35 +258,6 @@ pub fn vote_panel() -> Markup {\n }\n \n \n-pub fn demo_counter_panel(count: u64, event_log_path: &str) -> Markup {\n-    let rpc = template_json_compact(&serde_json::json!({ \"action\": \"bump_demo_counter\" }))\n-        .expect(\"rpc json\");\n-    html! {\n-        section id=\"demo-counter-panel\" class=\"demo-panel\" {\n-            h1 { \"sorter2\" }\n-            p class=\"muted\" {\n-                \"Pairwise ranking scaffold — votes persist to JSONL and replay on boot.\"\n-            }\n-            p class=\"demo-count\" {\n-                strong { \"Counter: \" }\n-                span id=\"demo-count-value\" { (count) }\n-            }\n-            p class=\"muted small\" {\n-                \"Event log: \" code { (event_log_path) }\n-            }\n-            form method=\"post\" action=\"/ui\" id=\"demo-bump-form\" {\n-                input type=\"hidden\" name=(UI_RPC_FIELD) value=(rpc);\n-                button type=\"submit\" class=\"btn-primary\" { \"Bump (POST /ui → eval JS)\" }\n-            }\n-            p class=\"muted small\" {\n-                \"Uses hidden \"\n-                code { \"__rpc__\" }\n-                \" JSON + Idiomorph morph — no full page reload.\"\n-            }\n-        }\n-    }\n-}\n-\n pub async fn home(\n     State(state): State<AppState>,\n     jar: CookieJar,\n@@ -297,16 +266,15 @@ pub async fn home(\n     let path = uri.path().to_string();\n     state.views.increment(path.clone());\n     let views = state.views.get_views(&path);\n-    let count = *state.demo_counter.read().await;\n     let theme = theme_from_jar(&jar);\n     let theme_next = theme_next_from_uri(&uri);\n-    let mut group = state.group.write().await;\n+    let group = state.group.read().await;\n     let empty_action = ParserAction::suggest(String::new(), None);\n     let body = html! {\n+        h1 { \"sorter2\" }\n         (parser_panel(\"\", &empty_action))\n         (vote_panel())\n-        (ranking_panel(&mut group))\n-        (demo_counter_panel(count, state.event_log.path().to_string_lossy().as_ref()))\n+        (ranking_panel(&group))\n     };\n     layout(\"sorter2\", body, views, theme, &theme_next)\n }\ndiff --git a/server/src/lib.rs b/server/src/lib.rs\nindex 6716c5b282e7980a7a0f03d63ad8b25eda61cc55..fa423640d598f4ba97a5885d228e78d7b97f7a22 100644\n--- a/server/src/lib.rs\n+++ b/server/src/lib.rs\n@@ -9,6 +9,7 @@ pub mod parser_render;\n pub mod path_types;\n pub mod ranking;\n pub mod reducer;\n+pub mod settlement;\n pub mod state;\n pub mod ui_action;\n pub mod views;\ndiff --git a/server/src/ranking.rs b/server/src/ranking.rs\nindex 89d3280126a8d8f841721ce8cb63ff735d68752a..2d706762792ba9239bb3f1c2e4974a2fde908013 100644\n--- a/server/src/ranking.rs\n+++ b/server/src/ranking.rs\n@@ -91,6 +91,11 @@ pub fn compute_group_ranking(group: &mut GroupState, max_iters: usize, tol: f64)\n \n pub fn ranked_items(group: &mut GroupState, max_iters: usize, tol: f64) -> Vec<RankedItem> {\n     compute_group_ranking(group, max_iters, tol);\n+    ranked_items_cached(group)\n+}\n+\n+/// Read cached scores without recomputing (HTTP fast path).\n+pub fn ranked_items_cached(group: &GroupState) -> Vec<RankedItem> {\n     let mut items: Vec<RankedItem> = group\n         .idx_to_item\n         .iter()\n@@ -105,7 +110,12 @@ pub fn ranked_items(group: &mut GroupState, max_iters: usize, tol: f64) -> Vec<R\n     items\n }\n \n-fn compute_scores_from_edges(n: usize, edges: impl Iterator<Item = ((usize, usize), f64)>, max_iters: usize, tol: f64) -> Vec<f64> {\n+pub fn compute_scores_from_edges(\n+    n: usize,\n+    edges: impl Iterator<Item = ((usize, usize), f64)>,\n+    max_iters: usize,\n+    tol: f64,\n+) -> Vec<f64> {\n     if n == 0 {\n         return vec![];\n     }\ndiff --git a/server/src/settlement.rs b/server/src/settlement.rs\nnew file mode 100644\nindex 0000000000000000000000000000000000000000..1f722ceaea62cda22c28ab71551f259fbf049b81\n--- /dev/null\n+++ b/server/src/settlement.rs\n@@ -0,0 +1,114 @@\n+use std::sync::Arc;\n+\n+use tokio::sync::{mpsc, oneshot, RwLock};\n+\n+use crate::{\n+    event_log::EventLog,\n+    events::Event,\n+    ranking::compute_scores_from_edges,\n+    reducer::{GroupState, VoteData},\n+};\n+\n+const MAX_ITERS: usize = 10_000;\n+const TOL: f64 = 1e-8;\n+\n+pub struct SettlementCommand {\n+    pub vote: VoteData,\n+    pub event: Event,\n+    pub reply: oneshot::Sender<Result<(), String>>,\n+}\n+\n+#[derive(Clone)]\n+pub struct SettlementClient {\n+    tx: mpsc::Sender<SettlementCommand>,\n+}\n+\n+impl SettlementClient {\n+    pub fn spawn(group: Arc<RwLock<GroupState>>, event_log: Arc<EventLog>) -> Self {\n+        let (tx, rx) = mpsc::channel(64);\n+        tokio::spawn(settlement_worker(rx, group, event_log));\n+        Self { tx }\n+    }\n+\n+    pub async fn record_vote(&self, vote: VoteData, event: Event) -> Result<(), String> {\n+        let (reply, rx) = oneshot::channel();\n+        self.tx\n+            .send(SettlementCommand {\n+                vote,\n+                event,\n+                reply,\n+            })\n+            .await\n+            .map_err(|_| \"settlement worker stopped\".to_string())?;\n+        rx.await\n+            .map_err(|_| \"settlement worker stopped\".to_string())?\n+    }\n+}\n+\n+async fn settlement_worker(\n+    mut rx: mpsc::Receiver<SettlementCommand>,\n+    group: Arc<RwLock<GroupState>>,\n+    event_log: Arc<EventLog>,\n+) {\n+    while let Some(first) = rx.recv().await {\n+        let mut batch = vec![first];\n+        while let Ok(more) = rx.try_recv() {\n+            batch.push(more);\n+        }\n+\n+        let mut disk_err: Option<String> = None;\n+        for cmd in &batch {\n+            if let Err(e) = event_log.append(&cmd.event).await {\n+                disk_err = Some(e.to_string());\n+                break;\n+            }\n+        }\n+\n+        if let Some(err) = disk_err {\n+            for cmd in batch {\n+                let _ = cmd.reply.send(Err(err.clone()));\n+            }\n+            continue;\n+        }\n+\n+        let (edges, n) = {\n+            let mut w = group.write().await;\n+            for cmd in &batch {\n+                w.apply_vote(cmd.vote.clone());\n+            }\n+            (w.edges.clone(), w.idx_to_item.len())\n+        };\n+\n+        let new_scores = compute_scores_from_edges(\n+            n,\n+            edges.iter().map(|(&k, &v)| (k, v)),\n+            MAX_ITERS,\n+            TOL,\n+        );\n+\n+        {\n+            let mut w = group.write().await;\n+            w.cached_scores = new_scores;\n+            w.dirty = false;\n+        }\n+\n+        for cmd in batch {\n+            let _ = cmd.reply.send(Ok(()));\n+        }\n+    }\n+}\n+\n+/// Compute ranking cache from current in-memory edges (startup replay only).\n+pub fn warm_ranking_cache(group: &mut GroupState) {\n+    if !group.dirty {\n+        return;\n+    }\n+    let n = group.idx_to_item.len();\n+    group.cached_scores = compute_scores_from_edges(\n+        n,\n+        group.edges.iter().map(|(&k, &v)| (k, v)),\n+        MAX_ITERS,\n+        TOL,\n+    );\n+    group.dirty = false;\n+}\ndiff --git a/server/src/state.rs b/server/src/state.rs\nindex 8ec9902e2ecc31cf8208f7ad6365891dc5537eed..1922541a4064c2de1df2d993a461cae783320e05 100644\n--- a/server/src/state.rs\n+++ b/server/src/state.rs\n@@ -6,6 +6,7 @@ use crate::{\n     event_log::EventLog,\n     events::Event,\n     reducer::{GroupState, VoteData},\n+    settlement::{warm_ranking_cache, SettlementClient},\n     views::ViewStore,\n };\n \n@@ -38,8 +39,8 @@ pub struct AppState {\n     pub cfg: Arc<AppConfig>,\n     pub event_log: Arc<EventLog>,\n     pub views: ViewStore,\n-    pub demo_counter: Arc<RwLock<u64>>,\n     pub group: Arc<RwLock<GroupState>>,\n+    settlement: SettlementClient,\n }\n \n impl AppState {\n@@ -48,14 +49,10 @@ impl AppState {\n         let views_path = format!(\"{}/views.json\", cfg.data_dir);\n         let views = ViewStore::new(&views_path);\n \n-        let mut demo_counter: u64 = 0;\n         let mut group = GroupState::new();\n         if let Ok((events, _)) = event_log.load_all().await {\n             for ev in events {\n                 match ev {\n-                    Event::DemoCounterBumped { value, .. } => {\n-                        demo_counter = demo_counter.max(value);\n-                    }\n                     Event::VoteRecorded {\n                         ts,\n                         a,\n@@ -74,30 +71,20 @@ impl AppState {\n             }\n         }\n \n+        warm_ranking_cache(&mut group);\n+\n+        let group = Arc::new(RwLock::new(group));\n+        let settlement = SettlementClient::spawn(group.clone(), event_log.clone());\n+\n         Self {\n             cfg: Arc::new(cfg),\n             event_log,\n             views,\n-            demo_counter: Arc::new(RwLock::new(demo_counter)),\n-            group: Arc::new(RwLock::new(group)),\n+            group,\n+            settlement,\n         }\n     }\n \n-    pub async fn bump_demo_counter(&self) -> u64 {\n-        let mut guard = self.demo_counter.write().await;\n-        *guard += 1;\n-        let value = *guard;\n-        drop(guard);\n-\n-        let ts = crate::html::now_ms();\n-        let _ = self\n-            .event_log\n-            .append(&Event::DemoCounterBumped { ts, value })\n-            .await;\n-\n-        value\n-    }\n-\n     pub async fn record_vote(\n         &self,\n         a: &str,\n@@ -109,23 +96,14 @@ impl AppState {\n         let vote = VoteData::from_recorded(ts, a, b, ratio_left, ratio_right)\n             .ok_or_else(|| \"invalid vote: need two distinct non-empty items\".to_string())?;\n \n-        {\n-            let mut group = self.group.write().await;\n-            group.apply_vote(vote.clone());\n-        }\n-\n-        let _ = self\n-            .event_log\n-            .append(&Event::VoteRecorded {\n-                ts,\n-                a: vote.a.as_str().to_string(),\n-                b: vote.b.as_str().to_string(),\n-                ratio_left: vote.ratio_left,\n-                ratio_right: vote.ratio_right,\n-            })\n-            .await\n-            .map_err(|e| e.to_string())?;\n+        let event = Event::VoteRecorded {\n+            ts,\n+            a: vote.a.as_str().to_string(),\n+            b: vote.b.as_str().to_string(),\n+            ratio_left: vote.ratio_left,\n+            ratio_right: vote.ratio_right,\n+        };\n \n-        Ok(())\n+        self.settlement.record_vote(vote, event).await\n     }\n }\ndiff --git a/server/src/ui_action.rs b/server/src/ui_action.rs\nindex 1d488e1ad1d8fd81bd9d016d69255adfe9b22fc8..5d94c84113607b3bcd8d31d03ef5b8e1b87b67a7 100644\n--- a/server/src/ui_action.rs\n+++ b/server/src/ui_action.rs\n@@ -12,8 +12,6 @@ pub const UI_RPC_FIELD: &str = \"__rpc__\";\n #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]\n #[serde(tag = \"action\", rename_all = \"snake_case\")]\n pub enum HtmlUiAction {\n-    /// Demo: morph `#demo-counter-panel` after bumping the persisted counter.\n-    BumpDemoCounter,\n     /// Record a pairwise vote and morph `#ranking-panel`.\n     RecordVote {\n         a: String,\n@@ -52,18 +50,6 @@ pub fn parse_html_ui_from_form(\n mod tests {\n     use super::*;\n \n-    #[test]\n-    fn bump_demo_counter_round_trip() {\n-        let template = serde_json::json!({ \"action\": \"bump_demo_counter\" });\n-        let mut form = HashMap::new();\n-        form.insert(\n-            UI_RPC_FIELD.to_string(),\n-            serde_json::to_string(&template).unwrap(),\n-        );\n-        let a = parse_html_ui_from_form(&form).unwrap();\n-        assert_eq!(a, HtmlUiAction::BumpDemoCounter);\n-    }\n-\n     #[test]\n     fn record_vote_round_trip_with_form_holes() {\n         let template = serde_json::json!({\ndiff --git a/server/tests/integration_health.rs b/server/tests/integration_health.rs\nindex 8a58bc14aac68c779e7ce4ffa57d27b3220e9953..1d816e008b9bf629967e3b3c786c41afefc284e3 100644\n--- a/server/tests/integration_health.rs\n+++ b/server/tests/integration_health.rs\n@@ -38,7 +38,7 @@ async fn healthz_ok() {\n }\n \n #[tokio::test]\n-async fn home_has_demo_panel() {\n+async fn home_has_main_panels() {\n     let (addr, _tmp) = start_test_server().await;\n     let client = reqwest::Client::new();\n     let html = client\ndiff --git a/server/tests/integration_ui.rs b/server/tests/integration_ui.rs\nindex bee79407dec120699a083f1a75adf9291e207fc7..7ede46d681fefbe25b1d98fc33520a185515eb1c 100644\n--- a/server/tests/integration_ui.rs\n+++ b/server/tests/integration_ui.rs\n@@ -25,33 +25,6 @@ async fn start_test_server() -> (SocketAddr, TempDir) {\n     (addr, tmp)\n }\n \n-#[tokio::test]\n-async fn post_ui_bump_returns_javascript_morph() {\n-    let (addr, tmp) = start_test_server().await;\n-    let rpc = serde_json::json!({ \"action\": \"bump_demo_counter\" }).to_string();\n-    let mut form = HashMap::new();\n-    form.insert(UI_RPC_FIELD.to_string(), rpc);\n-\n-    let client = reqwest::Client::new();\n-    let body = client\n-        .post(format!(\"http://{addr}/ui\"))\n-        .form(&form)\n-        .send()\n-        .await\n-        .unwrap()\n-        .text()\n-        .await\n-        .unwrap();\n-\n-    assert!(body.contains(\"Idiomorph.morph\"));\n-    assert!(body.contains(\"demo-counter-panel\"));\n-    assert!(body.contains(\"Counter:\"));\n-\n-    let log_path = tmp.path().join(\"events.jsonl\");\n-    let log = std::fs::read_to_string(log_path).unwrap();\n-    assert!(log.contains(\"demo_counter_bumped\"));\n-}\n-\n #[tokio::test]\n async fn post_ui_record_vote_morphs_ranking_and_persists() {\n     let (addr, tmp) = start_test_server().await;\n@@ -90,8 +63,8 @@ async fn post_ui_record_vote_morphs_ranking_and_persists() {\n         port: 0,\n     };\n     let state = create_app_state(cfg).await;\n-    let mut group = state.group.write().await;\n-    let ranked = sorter2_server::ranking::ranked_items(&mut group, 10_000, 1e-8);\n+    let group = state.group.read().await;\n+    let ranked = sorter2_server::ranking::ranked_items_cached(&group);\n     assert_eq!(ranked.len(), 2);\n     assert_eq!(ranked[0].item.as_str(), \"alpha\");\n }\ndiff --git a/test/smoke.clj b/test/smoke.clj\nindex b332324743b58baf3fe96d7477353749f137feae..11887c48282088e140d823a88ba616f6325835b3 100644\n--- a/test/smoke.clj\n+++ b/test/smoke.clj\n@@ -26,7 +26,7 @@\n             false))))))\n \n (deftest http-smoke-against-running-server\n-  (testing \"build, start, healthz, home contains RPC demo\"\n+  (testing \"build, start, healthz, home contains main panels\"\n     (let [root (repo-root)\n           data-dir (.getAbsolutePath (doto (io/file (System/getProperty \"java.io.tmpdir\")\n                                                    (str \"sorter2-smoke-\" (System/currentTimeMillis)))\n\n\nSide B — contributor: tommy-mor\nSide B — commit message:\n[04b81f91] Fix vote compare highlighting\n\nCo-authored-by: Cursor <cursoragent@cursor.com>\n\nSide B — unified diff (full patch):\ndiff --git a/server/src/html/mod.rs b/server/src/html/mod.rs\nindex 588cf62bcea608ed4ede363810f022a67b43b960..e180a0ca542a33e2300c0a4809e6b9cfee07ecfe 100644\n--- a/server/src/html/mod.rs\n+++ b/server/src/html/mod.rs\n@@ -291,18 +291,17 @@ fn rank_list(\n     label: &str,\n     items: &[RankedItem],\n     start_rank: usize,\n-    total_ranked: usize,\n-    ordinal_offset: usize,\n     highlighted: &HashSet<ItemId>,\n     tree: &GlobalTree,\n ) -> Markup {\n+    let group_len = items.len();\n     html! {\n         @if !items.is_empty() {\n             h3 class=\"rank-heading muted small\" { (label) }\n             ol class=\"rank-list\" {\n                 @for (i, r) in items.iter().enumerate() {\n                     @let href = item_href(&r.item);\n-                    @let style = rank_row_style(parent, ordinal_offset + i, total_ranked);\n+                    @let style = rank_row_style(parent, i, group_len);\n                     @let class = rank_row_class(&r.item, highlighted);\n                     li class=(class)\n                         data-rank-item=(r.item.as_str())\n@@ -420,8 +419,6 @@ pub fn ranking_panel_with_highlights(\n \n     let has_ranked = !ranked_groups.is_empty();\n     let multi = ranked_groups.len() > 1;\n-    let total_ranked: usize = ranked_groups.iter().map(|g| g.len()).sum();\n-    let mut ordinal_offset = 0usize;\n \n     html! {\n         section id=\"ranking-panel\" class=\"demo-panel\" {\n@@ -436,8 +433,7 @@ pub fn ranking_panel_with_highlights(\n             } @else {\n                 @for (gi, ranked) in ranked_groups.iter().enumerate() {\n                     @let label = if multi { format!(\"Ranking group {}\", gi + 1) } else { \"Ranking\".to_string() };\n-                    (rank_list(item, &label, ranked, 1, total_ranked, ordinal_offset, highlighted, tree))\n-                    @let _ = { ordinal_offset += ranked.len(); };\n+                    (rank_list(item, &label, ranked, 1, highlighted, tree))\n                 }\n                 (unranked_list(\"Unranked\", &unranked, highlighted, tree))\n             }\n@@ -520,7 +516,20 @@ pub async fn browse(State(state): State<AppState>, uri: Uri) -> impl IntoRespons\n \n #[cfg(test)]\n mod tests {\n-    use super::SORTER_UI_JS;\n+    use super::{rank_row_style, SORTER_UI_JS};\n+    use crate::path_types::ItemId;\n+\n+    #[test]\n+    fn rank_row_style_gradients_per_group_not_globally() {\n+        let parent = ItemId::opaque(\"test-scope\");\n+        let first_in_four = rank_row_style(&parent, 0, 4);\n+        let last_in_four = rank_row_style(&parent, 3, 4);\n+        let first_in_two = rank_row_style(&parent, 0, 2);\n+        let last_in_two = rank_row_style(&parent, 1, 2);\n+        assert_eq!(first_in_four, first_in_two);\n+        assert_eq!(last_in_four, last_in_two);\n+        assert_ne!(first_in_four, last_in_four);\n+    }\n \n     #[test]\n     fn vote_slider_left_position_favors_left_item() {\ndiff --git a/server/src/html/vote.rs b/server/src/html/vote.rs\nindex 483c7ff8cd35266744957cf0087f2b5f76f1a237..30dab303b9d1e763a5b9261dffff13a778e3e4e3 100644\n--- a/server/src/html/vote.rs\n+++ b/server/src/html/vote.rs\n@@ -19,7 +19,7 @@ use crate::{\n     ui_action::UI_RPC_FIELD,\n };\n \n-use super::{breadcrumb_path, item_href, layout};\n+use super::{breadcrumb_path, layout};\n \n #[derive(Debug, Deserialize)]\n pub struct VoteQuery {\n@@ -59,17 +59,6 @@ fn child_title(tree: &GlobalTree, id: &ItemId) -> String {\n         .unwrap_or_else(|| display_label(id))\n }\n \n-fn ratio_pct(ratio_left: i32, ratio_right: i32) -> f64 {\n-    let l = ratio_left.max(0) as f64;\n-    let r = ratio_right.max(0) as f64;\n-    let sum = l + r;\n-    if sum <= 0.0 {\n-        50.0\n-    } else {\n-        (l / sum) * 100.0\n-    }\n-}\n-\n fn ratios_for_page(v: &VoteData, page_left: &ItemId, page_right: &ItemId) -> (i32, i32) {\n     match (v.a.as_str(), v.b.as_str()) {\n         (a, b) if a == page_left.as_str() && b == page_right.as_str() => {\n@@ -94,6 +83,37 @@ fn edge_votes(group: &GroupState, left: &ItemId, right: &ItemId) -> Vec<VoteData\n         .collect()\n }\n \n+/// HUD `data-winner` value: which side the ratio favours on this page.\n+fn winner_side(r_left: i32, r_right: i32) -> &'static str {\n+    if r_left > r_right {\n+        \"left\"\n+    } else if r_right > r_left {\n+        \"right\"\n+    } else {\n+        \"even\"\n+    }\n+}\n+\n+fn winner_text(r_left: i32, r_right: i32) -> &'static str {\n+    match winner_side(r_left, r_right) {\n+        \"left\" => \"left wins\",\n+        \"right\" => \"right wins\",\n+        _ => \"tie\",\n+    }\n+}\n+\n+/// Map stored ratios to the live slider position (0 = full left, 100 = full right).\n+/// Matches `sorter_ui.js`: `left = 100 - v`, `right = v`.\n+fn slider_value_from_ratios(r_left: i32, r_right: i32) -> i32 {\n+    let l = r_left.max(0) as f64;\n+    let r = r_right.max(0) as f64;\n+    let sum = l + r;\n+    if sum <= 0.0 {\n+        return 50;\n+    }\n+    ((r / sum) * 100.0).round().clamp(0.0, 100.0) as i32\n+}\n+\n fn vote_edge_history(tree: &GlobalTree, group: &GroupState, left: &ItemId, right: &ItemId) -> Markup {\n     let mut votes = edge_votes(group, left, right);\n     votes.sort_by(|a, b| b.ts.cmp(&a.ts));\n@@ -106,17 +126,26 @@ fn vote_edge_history(tree: &GlobalTree, group: &GroupState, left: &ItemId, right\n             h3 class=\"vote-edge-history-title\" {\n                 \"votes on this pair\"\n             }\n+            p class=\"muted small vote-edge-legend\" {\n+                (format!(\"left: {legend_left} — right: {legend_right}\"))\n+            }\n             ul class=\"vote-edge-history\" {\n                 @for v in &votes {\n                     @let (r_left, r_right) = ratios_for_page(v, left, right);\n-                    @let pct = ratio_pct(r_left, r_right);\n+                    @let slider_val = slider_value_from_ratios(r_left, r_right);\n+                    @let side = winner_side(r_left, r_right);\n+                    @let label = winner_text(r_left, r_right);\n                     li class=\"vote-edge-history-row\" {\n                         div class=\"vote-edge-meta\" {\n                             span class=\"vote-edge-ratio\" { (format!(\"{}:{}\", r_left, r_right)) }\n+                            span class=\"vote-edge-winner muted small\" { \" · \" (label) }\n                         }\n-                        div class=\"ratio-bar vote-edge-bar\" aria-hidden=\"true\" {\n-                            div class=\"ratio-left\" style={(format!(\"width: {:.3}%;\", pct))} {}\n-                            div class=\"ratio-right\" style={(format!(\"width: {:.3}%;\", 100.0 - pct))} {}\n+                        label class=\"vote-hud-slider vote-edge-slider\" aria-hidden=\"true\" {\n+                            input type=\"range\" class=\"vote-edge-range\" min=\"0\" max=\"100\" value=(slider_val)\n+                                data-winner=(side)\n+                                style={(format!(\"--vote-slider-pct: {}%;\", slider_val))}\n+                                disabled\n+                                tabindex=\"-1\";\n                         }\n                     }\n                 }\n@@ -283,7 +312,6 @@ pub async fn vote_page(\n                         span class=\"vote-compare-vs\" { \"vs\" }\n                         (vote_compare_item_card(&tree, &right, \"vote-compare-right\"))\n                     }\n-                    (vote_back_nav(&parent))\n                     div id=\"vote-edge-history-region\" {\n                         (edge_history)\n                     }\n@@ -308,3 +336,66 @@ pub async fn vote_page(\n     )\n     .into_response()\n }\n+\n+#[cfg(test)]\n+mod polarity_tests {\n+    use super::*;\n+    use crate::ranking::ranked_items;\n+    use crate::reducer::GlobalTree;\n+\n+    fn id(s: &str) -> ItemId {\n+        ItemId::parse(s).unwrap()\n+    }\n+\n+    /// The page's left number must always equal the vote's weight for the\n+    /// item shown on the left, regardless of which order the vote stored a/b.\n+    #[test]\n+    fn ratios_for_page_orients_to_page_left() {\n+        let left = id(\"left_item\");\n+        let right = id(\"right_item\");\n+\n+        // Stored a == page left: keep order.\n+        let v1 = VoteData::from_recorded(1, left.as_str(), right.as_str(), 9, 1).unwrap();\n+        assert_eq!(ratios_for_page(&v1, &left, &right), (9, 1));\n+\n+        // Stored a == page right: swap so left stays left.\n+        let v2 = VoteData::from_recorded(2, right.as_str(), left.as_str(), 9, 1).unwrap();\n+        assert_eq!(ratios_for_page(&v2, &left, &right), (1, 9));\n+    }\n+\n+    #[test]\n+    fn winner_side_follows_larger_ratio() {\n+        assert_eq!(winner_side(9, 1), \"left\");\n+        assert_eq!(winner_side(1, 9), \"right\");\n+        assert_eq!(winner_side(1, 1), \"even\");\n+    }\n+\n+    #[test]\n+    fn slider_value_matches_hud_mapping() {\n+        assert_eq!(slider_value_from_ratios(9, 1), 10);\n+        assert_eq!(slider_value_from_ratios(1, 4), 80);\n+        assert_eq!(slider_value_from_ratios(1, 1), 50);\n+    }\n+\n+    /// End-to-end polarity invariant: a vote that favours the LEFT item (higher\n+    /// `ratio_left`, recorded as the RPC's `a`) must make that item rank #1.\n+    /// This is the property the UI must preserve: sliding left => left wins.\n+    #[test]\n+    fn sliding_left_makes_left_item_win_ranking() {\n+        let parent = id(\"scope\");\n+        let left = id(\"left_item\");\n+        let right = id(\"right_item\");\n+\n+        // Slider dragged left yields e.g. 9:1 with a = left item.\n+        let vote = VoteData::from_recorded(1, left.as_str(), right.as_str(), 9, 1).unwrap();\n+        let mut tree = GlobalTree::new();\n+        tree.apply_vote(&parent, vote);\n+\n+        let group = &tree.get(&parent).unwrap().local_ranking;\n+        let ranked = ranked_items(group);\n+        assert_eq!(\n+            ranked[0].item, left,\n+            \"left item should rank first when ratio favours the left\"\n+        );\n+    }\n+}\ndiff --git a/server/static/sorter.css b/server/static/sorter.css\nindex 5da967e8bfddc2bc34662fced841860f63f1ef36..bdd3d931365703705be08537a07f3ccaf975d3ea 100644\n--- a/server/static/sorter.css\n+++ b/server/static/sorter.css\n@@ -124,7 +124,7 @@ code {\n   z-index: 1;\n   box-shadow:\n     inset 0 0 0 3px var(--accent),\n-    inset 0 0 0 5px color-mix(in oklch, var(--rank-fg) 70%, transparent);\n+    inset 0 0 0 5px color-mix(in oklch, var(--rank-fg, var(--fg)) 70%, transparent);\n   filter: saturate(1.15) brightness(1.04);\n }\n \n@@ -320,7 +320,7 @@ h1 {\n   grid-template-columns: var(--vote-ratio-col) minmax(0, 1fr) var(--vote-actions-col);\n   gap: 0.5rem 0.65rem;\n   align-items: center;\n-  --vote-ratio-col: 3.25rem;\n+  --vote-ratio-col: 12.5rem;\n   --vote-actions-col: 11.5rem;\n }\n \n@@ -332,7 +332,7 @@ h1 {\n   margin: 0;\n   width: var(--vote-ratio-col);\n   min-width: var(--vote-ratio-col);\n-  text-align: center;\n+  text-align: right;\n   white-space: nowrap;\n }\n \n@@ -474,6 +474,16 @@ h1 {\n   --vote-track-muted: color-mix(in oklch, var(--muted) 55%, var(--bg));\n }\n \n+/* Center-anchored fill: the accent grows from the midpoint toward the thumb,\n+   so the highlighted mass always sits on the *winning* side (the side the\n+   thumb was dragged toward). Left winning => accent on the left half. */\n+.vote-hud-slider input[type=\"range\"][data-winner=\"even\"]::-webkit-slider-runnable-track {\n+  height: 0.65rem;\n+  border-radius: 0;\n+  border: 2px solid var(--border);\n+  background: var(--vote-track-muted);\n+}\n+\n .vote-hud-slider input[type=\"range\"][data-winner=\"left\"]::-webkit-slider-runnable-track {\n   height: 0.65rem;\n   border-radius: 0;\n@@ -483,7 +493,9 @@ h1 {\n     var(--vote-track-muted) 0%,\n     var(--vote-track-muted) var(--vote-slider-pct, 50%),\n     var(--accent) var(--vote-slider-pct, 50%),\n-    var(--accent) 100%\n+    var(--accent) 50%,\n+    var(--vote-track-muted) 50%,\n+    var(--vote-track-muted) 100%\n   );\n }\n \n@@ -493,7 +505,9 @@ h1 {\n   border: 2px solid var(--border);\n   background: linear-gradient(\n     to right,\n-    var(--accent) 0%,\n+    var(--vote-track-muted) 0%,\n+    var(--vote-track-muted) 50%,\n+    var(--accent) 50%,\n     var(--accent) var(--vote-slider-pct, 50%),\n     var(--vote-track-muted) var(--vote-slider-pct, 50%),\n     var(--vote-track-muted) 100%\n@@ -513,26 +527,35 @@ h1 {\n }\n \n .vote-hud-slider input[type=\"range\"][data-winner=\"left\"]::-moz-range-track,\n-.vote-hud-slider input[type=\"range\"][data-winner=\"right\"]::-moz-range-track {\n+.vote-hud-slider input[type=\"range\"][data-winner=\"right\"]::-moz-range-track,\n+.vote-hud-slider input[type=\"range\"][data-winner=\"even\"]::-moz-range-track {\n   height: 0.65rem;\n   border-radius: 0;\n   border: 2px solid var(--border);\n }\n \n+.vote-hud-slider input[type=\"range\"][data-winner=\"even\"]::-moz-range-track {\n+  background: var(--vote-track-muted);\n+}\n+\n .vote-hud-slider input[type=\"range\"][data-winner=\"left\"]::-moz-range-track {\n   background: linear-gradient(\n     to right,\n     var(--vote-track-muted) 0%,\n     var(--vote-track-muted) var(--vote-slider-pct, 50%),\n     var(--accent) var(--vote-slider-pct, 50%),\n-    var(--accent) 100%\n+    var(--accent) 50%,\n+    var(--vote-track-muted) 50%,\n+    var(--vote-track-muted) 100%\n   );\n }\n \n .vote-hud-slider input[type=\"range\"][data-winner=\"right\"]::-moz-range-track {\n   background: linear-gradient(\n     to right,\n-    var(--accent) 0%,\n+    var(--vote-track-muted) 0%,\n+    var(--vote-track-muted) 50%,\n+    var(--accent) 50%,\n     var(--accent) var(--vote-slider-pct, 50%),\n     var(--vote-track-muted) var(--vote-slider-pct, 50%),\n     var(--vote-track-muted) 100%\n@@ -573,20 +596,23 @@ h1 {\n   margin-bottom: 0.25rem;\n }\n \n-.ratio-bar {\n-  display: flex;\n-  height: 8px;\n-  border-radius: 0;\n-  overflow: hidden;\n-  background: var(--border);\n+/* Read-only sliders in vote history — same track/thumb styling as the HUD. */\n+.vote-edge-slider {\n+  display: block;\n+  margin-top: 0.15rem;\n }\n \n-.ratio-left {\n-  background: var(--accent);\n+.vote-edge-slider input[type=\"range\"] {\n+  pointer-events: none;\n+  cursor: default;\n+}\n+\n+.vote-edge-slider input[type=\"range\"]:disabled {\n+  opacity: 1;\n }\n \n-.ratio-right {\n-  background: var(--muted);\n+.vote-edge-legend {\n+  margin: 0 0 0.5rem;\n }\n \n @media (max-width: 900px) {\ndiff --git a/server/static/sorter_ui.js b/server/static/sorter_ui.js\nindex f665b45f4fd4771427dc4c37e563e4976873beee..5d6d765f69f301722e59248c76e919043559fb78 100644\n--- a/server/static/sorter_ui.js\n+++ b/server/static/sorter_ui.js\n@@ -138,6 +138,10 @@\n     function update() {\n       var v = parseInt(slider.value, 10);\n       if (!Number.isFinite(v)) v = 50;\n+      // Slider position drives the colored fill (a center-anchored bar that\n+      // grows toward whichever side is winning — see sorter.css). Sliding the\n+      // thumb left raises the left number; left winning keeps the accent mass\n+      // on the left, matching the \"votes on this pair\" history bars.\n       slider.style.setProperty('--vote-slider-pct', v + '%');\n       slider.setAttribute('aria-valuenow', String(v));\n       var left = Math.max(1, 100 - v);\n@@ -147,8 +151,12 @@\n       right = right / divisor;\n       if (leftInput) leftInput.value = String(left);\n       if (rightInput) rightInput.value = String(right);\n-      if (ratioDisplay) ratioDisplay.textContent = left + ':' + right;\n-      slider.dataset.winner = left >= right ? 'left' : 'right';\n+      var winner = left > right ? 'left' : (right > left ? 'right' : 'even');\n+      slider.dataset.winner = winner;\n+      if (ratioDisplay) {\n+        var label = winner === 'even' ? 'tie' : (winner + ' wins');\n+        ratioDisplay.textContent = left + ':' + right + ' \\u00b7 ' + label;\n+      }\n     }\n     slider.addEventListener('input', update);\n     update();\n","role":"user"}],"model":"openai/gpt-chat-latest"}