refactor(portal): move path and query helpers into module

adk-rust/crates/detmir-portal/src/path_query.rs

@@ -0,0 +1,54 @@
+//! URL path and query parsing helpers for the portal.
+//!
+//! CONTRACT: these helpers are routing glue. Keep accepted URL shapes stable
+//! because API handlers and the HTML portal depend on them.
+
+pub(crate) fn normalize_path(url: &str) -> String {
+    let path = url.split('?').next().unwrap_or("/");
+    let path = path.strip_prefix("/portal").unwrap_or(path);
+    if path.is_empty() {
+        "/".to_string()
+    } else {
+        path.to_string()
+    }
+}
+
+pub(crate) fn query_flag(url: &str, key: &str) -> bool {
+    let Some(query) = url.split_once('?').map(|(_, query)| query) else {
+        return false;
+    };
+    query.split('&').any(|pair| {
+        let (name, value) = pair.split_once('=').unwrap_or((pair, "1"));
+        name == key && matches!(value, "1" | "true" | "yes" | "on")
+    })
+}
+
+pub(crate) fn query_param(url: &str, key: &str) -> Option<String> {
+    let query = url.split_once('?').map(|(_, query)| query)?;
+    query.split('&').find_map(|pair| {
+        let (name, value) = pair.split_once('=').unwrap_or((pair, ""));
+        (name == key && !value.is_empty()).then(|| value.to_string())
+    })
+}
+
+pub(crate) fn parse_investigation_pack_path(path: &str) -> Option<String> {
+    path.strip_prefix("/api/investigation-pack/")
+        .map(str::trim)
+        .filter(|value| !value.is_empty() && !value.contains('/'))
+        .map(ToString::to_string)
+}
+
+pub(crate) fn parse_case_path(path: &str) -> Option<String> {
+    path.strip_prefix("/api/cases/")
+        .map(str::trim)
+        .filter(|value| !value.is_empty() && !value.contains('/'))
+        .map(ToString::to_string)
+}
+
+pub(crate) fn parse_case_status_path(path: &str) -> Option<String> {
+    path.strip_prefix("/api/cases/")
+        .and_then(|value| value.strip_suffix("/status"))
+        .map(str::trim)
+        .filter(|value| !value.is_empty() && !value.contains('/'))
+        .map(ToString::to_string)
+}