{"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[7bb7145d] url stuff\n\nSide A — unified diff (full patch):\ndiff --git a/AGENTS.md b/AGENTS.md\nindex e60b9ba6012593361ef10e8fdd9439cd9932e09b..babb889d6fbfb1fa7176c9e6b7544ae17b61dd2e 100644\n--- a/AGENTS.md\n+++ b/AGENTS.md\n@@ -58,4 +58,4 @@ Use **tmux** for `cargo run --package sorter2-server` (dev server). Rebuild afte\n \n - First `cargo test` / `cargo build --release` is slow; Clojure smoke test always does a release build.\n - `legacy/` and `ideas/` are not part of the workspace build.\n-- **ItemId** for web URLs is a canonical full URL (`https://reddit.com/r/rust`). Rules live in [`server/src/url_rules/`](server/src/url_rules/) (composable Rust, not a config DSL). After changing canonicalization rules, rebuild the projection: `cargo run --package sorter2-server -- replay-index`.\n+- **ItemId** for web URLs is a canonical full URL (`https://reddit.com/r/rust`). Rules live in [`server/src/url_rules/graph.rs`](server/src/url_rules/graph.rs): a semantic graph (DFA on host + path, query params in `Context`) with a generic internet fallback for unknown sites. After changing rules, rebuild the projection: `cargo run --package sorter2-server -- replay-index`.\ndiff --git a/server/src/url_rules/engine.rs b/server/src/url_rules/engine.rs\ndeleted file mode 100644\nindex e29b6b48c08deb7bffe031b1e542b1e25a7bef15..0000000000000000000000000000000000000000\n--- a/server/src/url_rules/engine.rs\n+++ /dev/null\n@@ -1,187 +0,0 @@\n-//! Composable URL normalization primitives.\n-\n-use std::collections::HashMap;\n-\n-use url::Url;\n-\n-/// Mutable URL view used by rule combinators before serializing to a canonical string.\n-#[derive(Debug, Clone)]\n-pub struct ParsedUrl {\n-    pub scheme: String,\n-    pub host: String,\n-    pub path_segments: Vec<String>,\n-    pub query: HashMap<String, String>,\n-    pub fragment: Option<String>,\n-}\n-\n-impl ParsedUrl {\n-    pub fn parse(raw: &str) -> Option<Self> {\n-        let trimmed = raw.trim();\n-        if trimmed.is_empty() {\n-            return None;\n-        }\n-\n-        let with_scheme = if trimmed.contains(\"://\") {\n-            trimmed.to_string()\n-        } else if trimmed.starts_with(\"r/\") || trimmed.starts_with(\"/r/\") {\n-            let rest = trimmed.trim_start_matches('/').trim_start_matches(\"r/\");\n-            format!(\"https://reddit.com/r/{rest}\")\n-        } else if trimmed.contains('.') && !trimmed.starts_with('/') {\n-            format!(\"https://{trimmed}\")\n-        } else {\n-            trimmed.to_string()\n-        };\n-\n-        let url = Url::parse(&with_scheme).ok()?;\n-        let host = url.host_str()?.to_string();\n-        let path_segments: Vec<String> = url\n-            .path_segments()\n-            .map(|segs| segs.filter(|s| !s.is_empty()).map(str::to_string).collect())\n-            .unwrap_or_default();\n-\n-        let mut query = HashMap::new();\n-        for (k, v) in url.query_pairs() {\n-            query.insert(k.into_owned(), v.into_owned());\n-        }\n-\n-        Some(Self {\n-            scheme: url.scheme().to_string(),\n-            path_segments,\n-            query,\n-            fragment: url.fragment().map(str::to_string),\n-            host,\n-        })\n-    }\n-\n-    pub fn with_path_segments(&self, segments: &[String]) -> Self {\n-        let mut u = self.clone();\n-        u.path_segments = segments.to_vec();\n-        u\n-    }\n-\n-    pub fn to_url(&self) -> Option<Url> {\n-        let mut url = if self.path_segments.is_empty() {\n-            Url::parse(&format!(\"{}://{}\", self.scheme, self.host)).ok()?\n-        } else {\n-            let path = format!(\"/{}\", self.path_segments.join(\"/\"));\n-            Url::parse(&format!(\"{}://{}{}\", self.scheme, self.host, path)).ok()?\n-        };\n-        if !self.query.is_empty() {\n-            let mut pairs: Vec<_> = self.query.iter().collect();\n-            pairs.sort_by(|a, b| a.0.cmp(b.0));\n-            url.query_pairs_mut().clear();\n-            for (k, v) in pairs {\n-                url.query_pairs_mut().append_pair(k, v);\n-            }\n-        }\n-        if let Some(ref frag) = self.fragment {\n-            url.set_fragment(Some(frag));\n-        }\n-        Some(url)\n-    }\n-\n-    pub fn canonical_string(&self) -> Option<String> {\n-        let url = self.to_url()?;\n-        let mut s = url.to_string();\n-        if self.path_segments.is_empty() {\n-            s = s.trim_end_matches('/').to_string();\n-        }\n-        Some(s)\n-    }\n-}\n-\n-pub fn force_https(u: &mut ParsedUrl) {\n-    if u.scheme == \"http\" {\n-        u.scheme = \"https\".to_string();\n-    }\n-}\n-\n-pub fn drop_fragment(u: &mut ParsedUrl) {\n-    u.fragment = None;\n-}\n-\n-pub fn strip_www(u: &mut ParsedUrl) {\n-    if u.host.starts_with(\"www.\") {\n-        u.host = u.host[4..].to_string();\n-    }\n-}\n-\n-pub fn lowercase_host(u: &mut ParsedUrl) {\n-    u.host = u.host.to_ascii_lowercase();\n-}\n-\n-pub fn lowercase_path(u: &mut ParsedUrl) {\n-    for seg in &mut u.path_segments {\n-        *seg = seg.to_ascii_lowercase();\n-    }\n-}\n-\n-pub fn clear_query(u: &mut ParsedUrl) {\n-    u.query.clear();\n-}\n-\n-pub fn keep_only_query(u: &mut ParsedUrl, keys: &[&str]) {\n-    u.query\n-        .retain(|k, _| keys.iter().any(|want| want == &k.as_str()));\n-}\n-\n-pub fn strip_tracking_params(u: &mut ParsedUrl) {\n-    u.query.retain(|k, _| {\n-        let lower = k.to_ascii_lowercase();\n-        !(lower.starts_with(\"utm_\")\n-            || matches!(\n-                lower.as_str(),\n-                \"fbclid\" | \"gclid\" | \"ref\" | \"ref_src\" | \"ref_source\" | \"mc_cid\" | \"mc_eid\"\n-            ))\n-    });\n-}\n-\n-pub fn truncate_after_segment(u: &mut ParsedUrl, name: &str, keep: usize) {\n-    if let Some(i) = u.path_segments.iter().position(|s| s == name) {\n-        let end = (i + 1 + keep).min(u.path_segments.len());\n-        u.path_segments.truncate(end);\n-    }\n-}\n-\n-pub fn drop_listing_suffix(u: &mut ParsedUrl, suffixes: &[&str]) {\n-    if u.path_segments.len() >= 3 && u.path_segments.first().map(String::as_str) == Some(\"r\") {\n-        if let Some(last) = u.path_segments.last() {\n-            if suffixes.iter().any(|s| *s == last.as_str()) {\n-                u.path_segments.pop();\n-            }\n-        }\n-    }\n-}\n-\n-pub fn normalize_reddit_host(u: &mut ParsedUrl) {\n-    if matches!(\n-        u.host.as_str(),\n-        \"old.reddit.com\" | \"new.reddit.com\" | \"www.reddit.com\"\n-    ) {\n-        u.host = \"reddit.com\".to_string();\n-    }\n-}\n-\n-pub fn rewrite_youtu_be(u: &mut ParsedUrl) {\n-    if u.host == \"youtu.be\" && u.path_segments.len() == 1 {\n-        let id = u.path_segments[0].clone();\n-        u.host = \"youtube.com\".to_string();\n-        u.path_segments = vec![\"watch\".to_string()];\n-        u.query.insert(\"v\".to_string(), id);\n-    }\n-}\n-\n-pub fn rewrite_youtube_shorts(u: &mut ParsedUrl) {\n-    if u.host == \"youtube.com\" && u.path_segments.first().map(String::as_str) == Some(\"shorts\") {\n-        if let Some(id) = u.path_segments.get(1).cloned() {\n-            u.path_segments = vec![\"watch\".to_string()];\n-            u.query.insert(\"v\".to_string(), id);\n-        }\n-    }\n-}\n-\n-pub fn normalize_youtube_host(u: &mut ParsedUrl) {\n-    if matches!(u.host.as_str(), \"m.youtube.com\" | \"www.youtube.com\") {\n-        u.host = \"youtube.com\".to_string();\n-    }\n-}\ndiff --git a/server/src/url_rules/mod.rs b/server/src/url_rules/mod.rs\nindex 03d53bd3e82d704a01ba3fd8dd02b7d31422c0de..9e1445346ce77a49dd6a7e7713bf9c57aef353cc 100644\n--- a/server/src/url_rules/mod.rs\n+++ b/server/src/url_rules/mod.rs\n@@ -1,8 +1,12 @@\n-//! URL canonicalization and hierarchy rules for [`crate::path_types::ItemId`].\n+//! URL canonicalization and hierarchy via a semantic graph (DFA + generic fallback).\n \n-mod engine;\n+mod graph;\n+mod parse;\n mod registry;\n \n+#[cfg(test)]\n+mod registry_tests;\n+\n pub use registry::{\n     canonicalize_raw, looks_like_url, navigable_breadcrumbs, parent_url, resolve_id, CanonicalResult,\n };\ndiff --git a/server/src/url_rules/registry.rs b/server/src/url_rules/registry.rs\nindex 14514e9af8385fb2b9b2f35eb9ee14d453d4b97c..8e6c012ea1fc74b864307bdacdf5a0f5db5259fc 100644\n--- a/server/src/url_rules/registry.rs\n+++ b/server/src/url_rules/registry.rs\n@@ -1,12 +1,7 @@\n-//! Per-domain canonicalization and hierarchy rules.\n+//! Public API: canonical identity and hierarchy via the URL graph.\n \n-use std::collections::HashSet;\n-\n-use super::engine::{\n-    clear_query, drop_fragment, drop_listing_suffix, force_https, keep_only_query, lowercase_host,\n-    lowercase_path, normalize_reddit_host, normalize_youtube_host, rewrite_youtu_be,\n-    rewrite_youtube_shorts, strip_tracking_params, strip_www, truncate_after_segment, ParsedUrl,\n-};\n+use super::graph::graph;\n+use super::parse::UrlParts;\n \n /// Result of canonicalizing a raw URL string.\n #[derive(Debug, Clone, PartialEq, Eq)]\n@@ -16,71 +11,16 @@ pub struct CanonicalResult {\n     pub alias_of: Option<String>,\n }\n \n-fn apply_global(u: &mut ParsedUrl) {\n-    force_https(u);\n-    drop_fragment(u);\n-    strip_www(u);\n-    lowercase_host(u);\n-    strip_tracking_params(u);\n-}\n-\n-fn normalize_reddit(u: &mut ParsedUrl) {\n-    normalize_reddit_host(u);\n-    lowercase_path(u);\n-    truncate_after_segment(u, \"comments\", 1);\n-    drop_listing_suffix(u, &[\"hot\", \"top\", \"new\", \"rising\", \"controversial\"]);\n-    clear_query(u);\n-}\n-\n-fn normalize_youtube(u: &mut ParsedUrl) {\n-    rewrite_youtu_be(u);\n-    normalize_youtube_host(u);\n-    rewrite_youtube_shorts(u);\n-    keep_only_query(u, &[\"v\", \"list\"]);\n-}\n-\n-fn normalize_default(_u: &mut ParsedUrl) {\n-    // Global rules only.\n-}\n-\n-fn domain_key(host: &str) -> &'static str {\n-    if host == \"reddit.com\" || host.ends_with(\".reddit.com\") {\n-        \"reddit.com\"\n-    } else if host == \"youtube.com\" || host == \"youtu.be\" {\n-        \"youtube.com\"\n-    } else {\n-        \"default\"\n-    }\n-}\n-\n-fn normalize_for_host(u: &mut ParsedUrl) {\n-    apply_global(u);\n-    match domain_key(&u.host) {\n-        \"reddit.com\" => normalize_reddit(u),\n-        \"youtube.com\" => normalize_youtube(u),\n-        _ => normalize_default(u),\n-    }\n-}\n-\n-/// Structural path segments that must not become standalone tree nodes when more path follows.\n-fn structural_trailing(host: &str) -> &'static [&'static str] {\n-    match domain_key(host) {\n-        \"reddit.com\" => &[\"comments\"],\n-        _ => &[],\n-    }\n-}\n-\n /// Canonicalize a raw URL. Returns `None` if the input is not URL-like.\n pub fn canonicalize_raw(raw: &str) -> Option<CanonicalResult> {\n     let trimmed = raw.trim();\n     if trimmed.is_empty() {\n         return None;\n     }\n-    let mut u = ParsedUrl::parse(trimmed)?;\n-    let input_snapshot = u.canonical_string()?;\n-    normalize_for_host(&mut u);\n-    let canonical = u.canonical_string()?;\n-    let alias_of = if input_snapshot != canonical {\n+    let parts = UrlParts::parse(trimmed)?;\n+    let g = graph();\n+    let canonical = g.resolve_canonical(&parts)?;\n+    let alias_of = if trimmed != canonical {\n         Some(trimmed.to_string())\n     } else {\n         None\n@@ -98,35 +38,14 @@ pub fn resolve_id(raw: &str) -> Option<String> {\n \n /// Navigable ancestor URLs from domain root up to and including `canonical` (full URLs).\n pub fn navigable_breadcrumbs(canonical: &str) -> Vec<String> {\n-    let Some(u) = ParsedUrl::parse(canonical) else {\n-        return vec![canonical.to_string()];\n+    let parts = match UrlParts::parse(canonical) {\n+        Some(p) => p,\n+        None => return vec![canonical.to_string()],\n     };\n-    let structural: HashSet<&str> = structural_trailing(&u.host).iter().copied().collect();\n-    let n = u.path_segments.len();\n-    let mut out = Vec::new();\n-\n-    // Domain root (no path segments).\n-    if let Some(base) = u.with_path_segments(&[]).canonical_string() {\n-        out.push(base);\n-    }\n-\n-    for i in 0..n {\n-        let segs: Vec<String> = u.path_segments[..=i].to_vec();\n-        let is_last = i == n - 1;\n-        let seg = u.path_segments[i].as_str();\n-        if structural.contains(seg) && !is_last {\n-            continue;\n-        }\n-        if let Some(url) = u.with_path_segments(&segs).canonical_string() {\n-            if out.last() != Some(&url) {\n-                out.push(url);\n-            }\n-        }\n-    }\n-    out\n+    graph().breadcrumbs(&parts)\n }\n \n-/// Immediate parent scope URL, or `None` for tree root / opaque single-segment ids.\n+/// Immediate parent scope URL, or `None` for tree root.\n pub fn parent_url(canonical: &str) -> Option<String> {\n     let crumbs = navigable_breadcrumbs(canonical);\n     if crumbs.len() <= 1 {\n@@ -148,88 +67,3 @@ pub fn looks_like_url(raw: &str) -> bool {\n         || t.starts_with(\"youtu.be/\")\n }\n \n-#[cfg(test)]\n-mod tests {\n-    use super::*;\n-\n-    #[test]\n-    fn reddit_post_drops_slug_and_normalizes_host() {\n-        let r = canonicalize_raw(\n-            \"https://old.reddit.com/r/AmItheAsshole/comments/1trnvdl/aita_for_cancelling/\",\n-        )\n-        .unwrap();\n-        assert_eq!(\n-            r.canonical,\n-            \"https://reddit.com/r/amitheasshole/comments/1trnvdl\"\n-        );\n-    }\n-\n-    #[test]\n-    fn reddit_strips_query_and_listing() {\n-        assert_eq!(\n-            canonicalize_raw(\"https://www.reddit.com/r/rust/?sort=top\")\n-                .unwrap()\n-                .canonical,\n-            \"https://reddit.com/r/rust\"\n-        );\n-        assert_eq!(\n-            canonicalize_raw(\"https://www.reddit.com/r/programming/hot\")\n-                .unwrap()\n-                .canonical,\n-            \"https://reddit.com/r/programming\"\n-        );\n-    }\n-\n-    #[test]\n-    fn reddit_short_path() {\n-        assert_eq!(\n-            canonicalize_raw(\"r/rust\").unwrap().canonical,\n-            \"https://reddit.com/r/rust\"\n-        );\n-    }\n-\n-    #[test]\n-    fn reddit_breadcrumbs_skip_phantom_comments() {\n-        let post = \"https://reddit.com/r/aww/comments/1trnvdl\";\n-        let crumbs = navigable_breadcrumbs(post);\n-        assert!(!crumbs.iter().any(|c| c.ends_with(\"/comments\")));\n-        assert_eq!(\n-            crumbs.last().map(String::as_str),\n-            Some(post)\n-        );\n-        assert!(crumbs.contains(&\"https://reddit.com/r/aww\".to_string()));\n-    }\n-\n-    #[test]\n-    fn reddit_parent_of_post_is_subreddit() {\n-        assert_eq!(\n-            parent_url(\"https://reddit.com/r/aww/comments/1trnvdl\").as_deref(),\n-            Some(\"https://reddit.com/r/aww\")\n-        );\n-    }\n-\n-    #[test]\n-    fn youtube_youtu_be_and_watch_same_canonical() {\n-        let a = canonicalize_raw(\"https://youtu.be/dQw4w9WgXcQ\").unwrap().canonical;\n-        let b = canonicalize_raw(\"https://www.youtube.com/watch?v=dQw4w9WgXcQ&t=10\").unwrap();\n-        assert_eq!(a, b.canonical);\n-        assert_eq!(a, \"https://youtube.com/watch?v=dQw4w9WgXcQ\");\n-    }\n-\n-    #[test]\n-    fn legacy_schemeless_upgrades() {\n-        assert_eq!(\n-            canonicalize_raw(\"reddit.com/r/rust/comments/aaa/announcing_rust_199\")\n-                .unwrap()\n-                .canonical,\n-            \"https://reddit.com/r/rust/comments/aaa\"\n-        );\n-    }\n-\n-    #[test]\n-    fn alias_recorded_when_input_differs() {\n-        let r = canonicalize_raw(\"https://youtu.be/abc123\").unwrap();\n-        assert_eq!(r.canonical, \"https://youtube.com/watch?v=abc123\");\n-        assert!(r.alias_of.is_some());\n-    }\n-}\n\n\nSide B — contributor: tommy-mor\nSide B — commit message:\n[7964b28f] fix\n\nSide B — unified diff (full patch):\ndiff --git a/Cargo.lock b/Cargo.lock\nindex 8c43fb75c472b102e6e1d3b837dce3355be898f2..e55d87f32ab32064686431c7082ef8c9ca872d63 100644\n--- a/Cargo.lock\n+++ b/Cargo.lock\n@@ -923,6 +923,15 @@ version = \"0.2.0\"\n source = \"registry+https://github.com/rust-lang/crates.io-index\"\n checksum = \"439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391\"\n \n+[[package]]\n+name = \"ppv-lite86\"\n+version = \"0.2.21\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9\"\n+dependencies = [\n+ \"zerocopy\",\n+]\n+\n [[package]]\n name = \"prettyplease\"\n version = \"0.2.37\"\n@@ -980,6 +989,36 @@ version = \"6.0.0\"\n source = \"registry+https://github.com/rust-lang/crates.io-index\"\n checksum = \"f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf\"\n \n+[[package]]\n+name = \"rand\"\n+version = \"0.8.6\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"5ca0ecfa931c29007047d1bc58e623ab12e5590e8c7cc53200d5202b69266d8a\"\n+dependencies = [\n+ \"libc\",\n+ \"rand_chacha\",\n+ \"rand_core\",\n+]\n+\n+[[package]]\n+name = \"rand_chacha\"\n+version = \"0.3.1\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88\"\n+dependencies = [\n+ \"ppv-lite86\",\n+ \"rand_core\",\n+]\n+\n+[[package]]\n+name = \"rand_core\"\n+version = \"0.6.4\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c\"\n+dependencies = [\n+ \"getrandom 0.2.17\",\n+]\n+\n [[package]]\n name = \"regex-automata\"\n version = \"0.4.14\"\n@@ -1270,6 +1309,7 @@ dependencies = [\n  \"dotenvy\",\n  \"futures-util\",\n  \"maud\",\n+ \"rand\",\n  \"reqwest\",\n  \"serde\",\n  \"serde_json\",\n@@ -1280,6 +1320,7 @@ dependencies = [\n  \"tower-http 0.5.2\",\n  \"tracing\",\n  \"tracing-subscriber\",\n+ \"urlencoding\",\n ]\n \n [[package]]\n@@ -1656,6 +1697,12 @@ dependencies = [\n  \"serde\",\n ]\n \n+[[package]]\n+name = \"urlencoding\"\n+version = \"2.1.3\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"daf8dba3b7eb870caf1ddeed7bc9d2a049f3cfdfae7cb521b087cc33ae4c49da\"\n+\n [[package]]\n name = \"utf8_iter\"\n version = \"1.0.4\"\n@@ -2052,6 +2099,26 @@ dependencies = [\n  \"synstructure\",\n ]\n \n+[[package]]\n+name = \"zerocopy\"\n+version = \"0.8.50\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"3b065d4f0e55f82fae73202e189638116a87c55ab6b8e6c2721e13dd9d854ad1\"\n+dependencies = [\n+ \"zerocopy-derive\",\n+]\n+\n+[[package]]\n+name = \"zerocopy-derive\"\n+version = \"0.8.50\"\n+source = \"registry+https://github.com/rust-lang/crates.io-index\"\n+checksum = \"0b631b19d36a892ab55420c92dbc83ccd79274f25be714855d3074aa71cab639\"\n+dependencies = [\n+ \"proc-macro2\",\n+ \"quote\",\n+ \"syn\",\n+]\n+\n [[package]]\n name = \"zerofrom\"\n version = \"0.1.8\"\ndiff --git a/server/Cargo.toml b/server/Cargo.toml\nindex c940acb687fb141d21760a3d6656172013cf6f41..6fb7bf52fa58f46f5e8fb0f7fd395247b57506d7 100644\n--- a/server/Cargo.toml\n+++ b/server/Cargo.toml\n@@ -20,6 +20,8 @@ reqwest = { version = \"0.12\", features = [\"json\"] }\n dotenvy = \"0.15\"\n async-stream = \"0.3\"\n futures-util = { version = \"0.3\", default-features = false, features = [\"std\"] }\n+rand = \"0.8\"\n+urlencoding = \"2\"\n \n [dev-dependencies]\n reqwest = { version = \"0.12\", features = [\"json\"] }\ndiff --git a/server/src/api/ui_html.rs b/server/src/api/ui_html.rs\nindex e649a7d192feade465e19ce6187a829f6ec74372..06001212820101e0cc953d3687dea64f85e60787 100644\n--- a/server/src/api/ui_html.rs\n+++ b/server/src/api/ui_html.rs\n@@ -47,6 +47,7 @@ pub async fn post_ui_html(\n             ratio_left,\n             ratio_right,\n             scope,\n+            next,\n         } => {\n             let parent = parent_from_scope(&scope);\n             if let Err(e) = state\n@@ -56,9 +57,19 @@ pub async fn post_ui_html(\n                 return ui_js_warn(&e).into_response();\n             }\n             let tree = state.tree.read().await;\n+            if !next.trim().is_empty() {\n+                drop(tree);\n+                return JsBuilder::new()\n+                    .raw(&format!(\n+                        \"window.location.href={};\",\n+                        js_string_literal(next.trim())\n+                    ))\n+                    .into_response();\n+            }\n             let empty = crate::reducer::NodeState::default();\n             let node = tree.get(&parent).unwrap_or(&empty);\n             let panel = ranking_panel(&parent, node, &tree);\n+            drop(tree);\n             JsBuilder::new()\n                 .morph_selector(\"#ranking-panel\", panel)\n                 .into_response()\n@@ -126,6 +137,7 @@ mod tests {\n                 ratio_left: 3,\n                 ratio_right: 1,\n                 scope: String::new(),\n+                next: String::new(),\n             }\n         );\n     }\ndiff --git a/server/src/form_template.rs b/server/src/form_template.rs\nindex b9bc3982a125e94e67c99175ea9055979541abba..bd4a7195a6eaabfed55333bab5640708ea108b81 100644\n--- a/server/src/form_template.rs\n+++ b/server/src/form_template.rs\n@@ -7,19 +7,30 @@ pub fn template_json_compact<T: Serialize>(v: &T) -> serde_json::Result<String>\n     serde_json::to_string(v)\n }\n \n-/// Recursively walk the JSON AST and replace `{\"$form\": \"key\"}` with the submitted\n-/// string for `key` (empty if missing). Other keys are unchanged.\n+/// Recursively walk the JSON AST and replace form holes with submitted values.\n+///\n+/// - `{\"$form\": \"key\"}` → string (empty if missing)\n+/// - `{\"$form:i32\": \"key\"}` → JSON number (0 if missing or unparseable)\n pub fn substitute_form_vars(val: &mut Value, form_data: &HashMap<String, String>) {\n     match val {\n         Value::Object(map) => {\n             if map.len() == 1 {\n-                if let Some(Value::String(field_name)) = map.get(\"$form\") {\n-                    let submitted = form_data\n-                        .get(field_name.as_str())\n-                        .map(|s| s.as_str())\n-                        .unwrap_or(\"\");\n-                    *val = Value::String(submitted.to_string());\n-                    return;\n+                if let Some((hole_key, Value::String(field_name))) = map.iter().next() {\n+                    if let Some(form_type) = hole_key.strip_prefix(\"$form\") {\n+                        let submitted = form_data\n+                            .get(field_name.as_str())\n+                            .map(|s| s.as_str())\n+                            .unwrap_or(\"\");\n+                        *val = match form_type {\n+                            \"\" => Value::String(submitted.to_string()),\n+                            \":i32\" => {\n+                                let n: i32 = submitted.trim().parse().unwrap_or(0);\n+                                Value::Number(n.into())\n+                            }\n+                            _ => Value::String(submitted.to_string()),\n+                        };\n+                        return;\n+                    }\n                 }\n             }\n             for v in map.values_mut() {\n@@ -62,6 +73,45 @@ mod tests {\n         text: String,\n     }\n \n+    #[test]\n+    fn i32_holes_become_numbers() {\n+        let json = r#\"{\n+            \"ratio_left\": {\"$form:i32\": \"ratio_left\"},\n+            \"ratio_right\": {\"$form:i32\": \"ratio_right\"}\n+        }\"#;\n+        let mut form = HashMap::new();\n+        form.insert(\"ratio_left\".into(), \"75\".into());\n+        form.insert(\"ratio_right\".into(), \"25\".into());\n+        let v = fill_template_from_form(json, &form).unwrap();\n+        assert_eq!(v[\"ratio_left\"], 75);\n+        assert_eq!(v[\"ratio_right\"], 25);\n+\n+        #[derive(Debug, Deserialize, PartialEq, Eq)]\n+        struct Ratios {\n+            ratio_left: i32,\n+            ratio_right: i32,\n+        }\n+        let r: Ratios = serde_json::from_value(v).unwrap();\n+        assert_eq!(\n+            r,\n+            Ratios {\n+                ratio_left: 75,\n+                ratio_right: 25,\n+            }\n+        );\n+    }\n+\n+    #[test]\n+    fn i32_hole_missing_or_bad_defaults_to_zero() {\n+        let json = r#\"{\"n\": {\"$form:i32\": \"missing\"}}\"#;\n+        let v = fill_template_from_form(json, &HashMap::new()).unwrap();\n+        assert_eq!(v[\"n\"], 0);\n+        let mut form = HashMap::new();\n+        form.insert(\"missing\".into(), \"nope\".into());\n+        let v = fill_template_from_form(json, &form).unwrap();\n+        assert_eq!(v[\"n\"], 0);\n+    }\n+\n     #[test]\n     fn holes_become_strings() {\n         let json = r#\"{\ndiff --git a/server/src/html/mod.rs b/server/src/html/mod.rs\nindex 3bf9fc7e92e50beed24e2c25106a77421038c90b..61cdbc094819ddedb755572c59456ec0d6617619 100644\n--- a/server/src/html/mod.rs\n+++ b/server/src/html/mod.rs\n@@ -20,6 +20,8 @@ use crate::{\n     ui_action::UI_RPC_FIELD,\n };\n \n+pub mod vote;\n+\n const SORTER_CSS: &str = include_str!(\"../../static/sorter.css\");\n const SORTER_UI_JS: &str = include_str!(\"../../static/sorter_ui.js\");\n \n@@ -131,7 +133,7 @@ fn layout(title: &str, body: Markup, views: u64) -> Markup {\n     }\n }\n \n-fn item_href(id: &ItemId) -> String {\n+pub(crate) fn item_href(id: &ItemId) -> String {\n     id.browse_href()\n }\n \n@@ -309,11 +311,23 @@ async fn item_page(state: AppState, uri: Uri, item: ItemId) -> Markup {\n     let empty_node = NodeState::default();\n     let node = tree.get(&item).unwrap_or(&empty_node);\n \n+    let child_count = node.children.len();\n+    let vote_link = if child_count >= 2 {\n+        Some(vote::vote_href(&item))\n+    } else {\n+        None\n+    };\n+\n     let body = html! {\n         h1 { \"sorter\" }\n         (input_panel(\"\", None))\n         (breadcrumb_path(&item))\n         (entity_section(&item, node, false))\n+        @if let Some(href) = vote_link {\n+            p class=\"vote-cta\" {\n+                a class=\"btn-primary\" href=(href) data-testid=\"vote-children\" { \"Vote on children\" }\n+            }\n+        }\n         (ranking_panel(&item, node, &tree))\n     };\n     layout(\"sorter2\", body, views)\ndiff --git a/server/src/lib.rs b/server/src/lib.rs\nindex da5f3ebecec1794b05a2a69cc78379551b2ad769..7f7e28c8ac3758de87f1f8e073b24be4132d38da 100644\n--- a/server/src/lib.rs\n+++ b/server/src/lib.rs\n@@ -4,6 +4,7 @@ pub mod events;\n pub mod fetch;\n pub mod form_template;\n pub mod html;\n+pub mod pair;\n pub mod parser;\n pub mod path_types;\n pub mod ranking;\n@@ -33,6 +34,7 @@ pub fn create_app(state: AppState) -> Router {\n         .route(\"/static/:filename\", get(crate::html::serve_static))\n         .route(\"/~/*item_path\", get(crate::html::browse))\n         .route(\"/\", get(crate::html::home))\n+        .route(\"/vote\", get(crate::html::vote::vote_page))\n         .route(\"/ui\", post(crate::api::ui_html::post_ui_html))\n         .with_state(state)\n         .layer(TraceLayer::new_for_http())\ndiff --git a/server/src/ui_action.rs b/server/src/ui_action.rs\nindex 2047713762c932ac9bc325fe15624f2aecb3364d..53581e1362bfcc5dfb4ae3069c41ea6f7be41437 100644\n--- a/server/src/ui_action.rs\n+++ b/server/src/ui_action.rs\n@@ -31,6 +31,9 @@ pub enum HtmlUiAction {\n         /// Parent node [`ItemId`] string; empty = tree root.\n         #[serde(default)]\n         scope: String,\n+        /// After vote, navigate here (vote compare page).\n+        #[serde(default)]\n+        next: String,\n     },\n     /// Parse pasted Reddit URL/path; redirect to subreddit ranking on success.\n     ParseQuery {\n@@ -70,6 +73,36 @@ pub fn parse_html_ui_from_form(\n mod tests {\n     use super::*;\n \n+    #[test]\n+    fn record_vote_round_trip_with_typed_ratio_holes() {\n+        let template = serde_json::json!({\n+            \"action\": \"record_vote\",\n+            \"a\": \"x\",\n+            \"b\": \"y\",\n+            \"ratio_left\": {\"$form:i32\": \"ratio_left\"},\n+            \"ratio_right\": {\"$form:i32\": \"ratio_right\"},\n+            \"scope\": \"parent\",\n+        });\n+        let mut form = HashMap::new();\n+        form.insert(\n+            UI_RPC_FIELD.to_string(),\n+            serde_json::to_string(&template).unwrap(),\n+        );\n+        form.insert(\"ratio_left\".into(), \"60\".into());\n+        form.insert(\"ratio_right\".into(), \"40\".into());\n+        assert_eq!(\n+            parse_html_ui_from_form(&form).unwrap(),\n+            HtmlUiAction::RecordVote {\n+                a: \"x\".into(),\n+                b: \"y\".into(),\n+                ratio_left: 60,\n+                ratio_right: 40,\n+                scope: \"parent\".into(),\n+                next: String::new(),\n+            }\n+        );\n+    }\n+\n     #[test]\n     fn record_vote_round_trip_with_form_holes() {\n         let template = serde_json::json!({\n@@ -96,6 +129,7 @@ mod tests {\n                 ratio_left: 2,\n                 ratio_right: 1,\n                 scope: \"amitheasshole\".into(),\n+                next: String::new(),\n             }\n         );\n     }\n@@ -122,6 +156,7 @@ mod tests {\n                 ratio_left: 2,\n                 ratio_right: 1,\n                 scope: String::new(),\n+                next: String::new(),\n             }\n         );\n     }\ndiff --git a/server/static/sorter.css b/server/static/sorter.css\nindex 021918f8e778b84e4b3eac8559fab7d223a3d490..3c2cec5cb5094013387147c621d75bd341bc06cc 100644\n--- a/server/static/sorter.css\n+++ b/server/static/sorter.css\n@@ -224,4 +224,148 @@ code {\n \n h1 {\n   margin: 0;\n+}\n+\n+.vote-cta {\n+  margin: 0.75rem 0;\n+}\n+\n+.vote-compare-shell {\n+  max-width: 960px;\n+}\n+\n+.vote-compare-scope {\n+  margin: 0.5rem 0 1rem;\n+}\n+\n+.vote-compare-pair {\n+  display: grid;\n+  grid-template-columns: 1fr auto 1fr;\n+  gap: 1rem;\n+  align-items: start;\n+  margin: 1rem 0;\n+}\n+\n+.vote-compare-vs {\n+  align-self: center;\n+  font-size: 1.25rem;\n+  color: var(--muted);\n+  font-weight: 600;\n+}\n+\n+.vote-compare-side {\n+  background: var(--panel);\n+  border: 1px solid var(--border);\n+  border-radius: 8px;\n+  padding: 1rem;\n+  min-height: 120px;\n+}\n+\n+.vote-compare-item {\n+  color: var(--accent);\n+  text-decoration: none;\n+  display: block;\n+}\n+\n+.vote-compare-item:hover {\n+  text-decoration: underline;\n+}\n+\n+.vote-compare-figure {\n+  margin: 0.75rem 0 0;\n+}\n+\n+.vote-compare-image {\n+  display: block;\n+  max-width: 100%;\n+  height: auto;\n+  border-radius: 6px;\n+  border: 1px solid var(--border);\n+}\n+\n+.vote-compare-item-body {\n+  margin-top: 0.75rem;\n+  font-size: 0.9rem;\n+}\n+\n+.vote-compare-nav {\n+  display: flex;\n+  justify-content: space-between;\n+  align-items: center;\n+  gap: 1rem;\n+  margin: 1rem 0;\n+}\n+\n+.vote-compare-next {\n+  color: var(--accent);\n+  text-decoration: none;\n+}\n+\n+.vote-compare-next.is-disabled {\n+  color: var(--muted);\n+}\n+\n+.vote-compare-back {\n+  text-decoration: none;\n+}\n+\n+.vote-compare-back:hover {\n+  text-decoration: underline;\n+}\n+\n+.vote-compare-slider-label {\n+  display: grid;\n+  grid-template-columns: 1fr auto 1fr;\n+  gap: 0.75rem;\n+  align-items: center;\n+  margin: 1.25rem 0;\n+}\n+\n+.vote-compare-slider-label input[type=\"range\"] {\n+  width: 100%;\n+  min-width: 160px;\n+}\n+\n+#vote-slider-left-label {\n+  text-align: right;\n+}\n+\n+#vote-slider-right-label {\n+  text-align: left;\n+}\n+\n+.vote-edge-history-title {\n+  margin: 1.5rem 0 0.5rem;\n+  font-size: 1rem;\n+}\n+\n+.vote-edge-history {\n+  list-style: none;\n+  padding: 0;\n+  margin: 0;\n+}\n+\n+.vote-edge-history-row {\n+  margin-bottom: 0.75rem;\n+}\n+\n+.vote-edge-meta {\n+  font-size: 0.875rem;\n+  margin-bottom: 0.25rem;\n+}\n+\n+.ratio-bar {\n+  display: flex;\n+  height: 8px;\n+  border-radius: 4px;\n+  overflow: hidden;\n+  background: var(--border);\n+}\n+\n+.ratio-left {\n+  background: var(--accent);\n+}\n+\n+.ratio-right {\n+  background: var(--muted);\n }\n\\ No newline at end of file\ndiff --git a/server/static/sorter_ui.js b/server/static/sorter_ui.js\nindex 62c9158ecb3c2140b83efd2b27ea706a9e0ae127..c8d7c3ef2413399ced7898a7edb3e7a2c8e16163 100644\n--- a/server/static/sorter_ui.js\n+++ b/server/static/sorter_ui.js\n@@ -81,7 +81,22 @@\n     });\n   }\n \n+  function initVoteSlider() {\n+    var slider = document.getElementById('vote-preference-slider');\n+    if (!slider) return;\n+    var leftInput = document.getElementById('vote-ratio-left');\n+    var rightInput = document.getElementById('vote-ratio-right');\n+    function update() {\n+      var v = parseInt(slider.value, 10);\n+      if (leftInput) leftInput.value = String(v);\n+      if (rightInput) rightInput.value = String(100 - v);\n+    }\n+    slider.addEventListener('input', update);\n+    update();\n+  }\n+\n   function initSorterUi() {\n+    initVoteSlider();\n     document.addEventListener('submit', async function (e) {\n       var f = e.target;\n       if (!f || f.tagName !== 'FORM') return;\n@@ -89,10 +104,11 @@\n       if (f.getAttribute('data-navigate') === 'full') return;\n       e.preventDefault();\n       await postUiForm(f);\n-      if (f.id === 'vote-form') {\n+      if (f.id === 'vote-form' || f.id === 'vote-compare-form') {\n         f.reset();\n-        var firstField = f.querySelector('input[type=\"text\"]');\n-        if (firstField) firstField.focus();\n+        var slider = f.querySelector('#vote-preference-slider');\n+        if (slider) slider.value = '50';\n+        initVoteSlider();\n       }\n     });\n   }\n","role":"user"}],"model":"~x-ai/grok-latest"}