feat: server-authoritative case window via users.toml

The /api/oneliners time window is now read per-user from users.toml
(window_hours, default 72h). Clients no longer carry a window:
client.toml oneliner_window_hours, SyncConfig.window_hours, the
?hours=N query param, and the render_case_list cutoff filter are
gone. ETag suffix keeps the effective hours so an admin edit to
users.toml invalidates client caches on the next request.
OnelinersResponse.window_hours stays in the wire format, but now
exists solely to anchor client reconciliation.

doctate-client-core/src/config.rs

@@ -15,9 +15,6 @@ use thiserror::Error;
 /// Fallback polling cadence for `/api/oneliners` in seconds. Chosen to
 /// feel real-time without hammering the server.
 pub const DEFAULT_POLL_INTERVAL_SECONDS: u64 = 5;
-/// Fallback window passed as `?hours=N` to `/api/oneliners`. 72 h so
-/// Monday-morning shows Friday's unfinished work.
-pub const DEFAULT_ONELINER_WINDOW_HOURS: u32 = 72;
 
 /// Client configuration loaded from a TOML file at a platform-specific
 /// path. All fields except the two durations are mandatory.
@@ -31,10 +28,6 @@ pub struct Config {
     /// built-in default.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub oneliner_poll_interval_seconds: Option<u64>,
-    /// Time window handed to the server as `?hours=N`. Omit in TOML to
-    /// use the built-in default.
-    #[serde(default, skip_serializing_if = "Option::is_none")]
-    pub oneliner_window_hours: Option<u32>,
 }
 
 #[derive(Debug, Error)]
@@ -103,12 +96,6 @@ impl Config {
                 .unwrap_or(DEFAULT_POLL_INTERVAL_SECONDS),
         )
     }
-
-    /// Window-hours parameter for `/api/oneliners`, with default.
-    pub fn window_hours(&self) -> u32 {
-        self.oneliner_window_hours
-            .unwrap_or(DEFAULT_ONELINER_WINDOW_HOURS)
-    }
 }
 
 #[cfg(test)]
@@ -121,7 +108,6 @@ mod tests {
             server_url: "https://doctate.example.org".into(),
             api_key: "sk-test-12345".into(),
             oneliner_poll_interval_seconds: None,
-            oneliner_window_hours: None,
         }
     }
 
@@ -166,7 +152,6 @@ mod tests {
         std::fs::write(&path, "server_url = \"http://x\"\napi_key = \"y\"\n").unwrap();
         let cfg = Config::load_from(&path).unwrap().unwrap();
         assert_eq!(cfg.poll_interval(), Duration::from_secs(5));
-        assert_eq!(cfg.window_hours(), 72);
     }
 
     #[test]
@@ -175,10 +160,8 @@ mod tests {
             server_url: "http://x".into(),
             api_key: "y".into(),
             oneliner_poll_interval_seconds: Some(10),
-            oneliner_window_hours: Some(24),
         };
         assert_eq!(cfg.poll_interval(), Duration::from_secs(10));
-        assert_eq!(cfg.window_hours(), 24);
     }
 
     #[test]
@@ -189,11 +172,9 @@ mod tests {
             server_url: "http://x".into(),
             api_key: "y".into(),
             oneliner_poll_interval_seconds: Some(3),
-            oneliner_window_hours: Some(168),
         };
         original.save_to(&path).unwrap();
         let loaded = Config::load_from(&path).unwrap().unwrap();
         assert_eq!(loaded.oneliner_poll_interval_seconds, Some(3));
-        assert_eq!(loaded.oneliner_window_hours, Some(168));
     }
 }