Move Proclamations From Sub-Categories To Groups

The portal's v2 API replaced nested categories (proclamation_categories.parent_id)
with flat categories plus tag-like groups: a proclamation now belongs to one
category and optionally one group. This lets the Proclamation Options page drop
its special-cased two-level tree.

Database:
- Add the proclamation_groups table (id, name, sort_order) and a
  proclamations.group_id column.
- Drop parent_id from the proclamation_categories DDL so fresh databases get a
  flat table.
- runMigrations() creates the new table/column, then runs a one-time
  transactional v1->v2 migration keyed on PRAGMA user_version: every legacy
  sub-category becomes a group (its id is preserved), proclamations that
  pointed at a sub-category are remapped to (parent category, new group), and
  the now-stale sub-category rows are deleted. selected flags are never
  touched, so user choices survive. No network is needed, so offline kiosks
  migrate at startup; re-running is a no-op.
- Add replaceGroups() and getAllGroups(); stop reading/writing parent_id.

API sync:
- Add PATH_GROUPS ("/groups") and parseGroupsJson().
- parseProclamationsJson() now also reads groupId.
- syncProclamationsFromApi() fetches /proclamations, /categories and /groups,
  leaves the database untouched if any request or parse fails, then replaces
  categories, replaces groups and upserts proclamations.

Proclamation Options page:
- FlatItem is now Category / Group / Proclamation.
- Each category lists only the groups that have at least one member in that
  category, so impossible pairings (e.g. Physical/Prayers) never render.
- Proclamations with no group, or with a group the portal has removed, sit
  directly under the category. Groups are collapsible and use a distinct color.

Tests:
- test_db: groups round-trip plus a legacy->v2 migration test asserting the
  group is created, proclamations are remapped, selection is preserved and a
  second initialize() is a no-op.
- test_proclamation_sync / test_api_client: parse groupId, parse groups, and
  the live smoke test now also fetches /groups.

Docs: README database table and AGENTS notes updated for groups.

src/network/proclamation_sync.cpp

@@ -66,6 +66,7 @@ bool parseProclamationsJson(const std::string& body,
         rec.title = stripHtml(entry.stringField("name"));
         rec.content = stripHtml(entry.stringField("content"));
         rec.category_id = static_cast<int>(entry.numberField("categoryId"));
+        rec.group_id = static_cast<int>(entry.numberField("groupId"));
         rec.solfeggio_frequency_id = static_cast<int>(entry.numberField("solfeggioFrequencyId"));
         out.push_back(std::move(rec));
     }
@@ -88,7 +89,28 @@ bool parseCategoriesJson(const std::string& body,
         if (rec.id == 0) continue;
 
         rec.name = entry.stringField("name");
-        rec.parent_id = static_cast<int>(entry.numberField("parentId"));
+        rec.sort_order = static_cast<int>(entry.numberField("sortOrder"));
+        out.push_back(std::move(rec));
+    }
+    return true;
+}
+
+bool parseGroupsJson(const std::string& body,
+                     std::vector<radiantwave::db::ProclamationGroupRecord>& out) {
+    json::JsonValue root;
+    if (!json::parseDocument(body, root) || root.type != json::JsonValue::Type::Array) {
+        return false;
+    }
+
+    out.clear();
+    for (const auto& entry : root.array) {
+        if (entry.type != json::JsonValue::Type::Object) continue;
+
+        radiantwave::db::ProclamationGroupRecord rec;
+        rec.id = static_cast<int>(entry.numberField("id"));
+        if (rec.id == 0) continue;
+
+        rec.name = entry.stringField("name");
         rec.sort_order = static_cast<int>(entry.numberField("sortOrder"));
         out.push_back(std::move(rec));
     }
@@ -114,16 +136,28 @@ bool syncProclamationsFromApi(radiantwave::db::DatabaseManager& db,
         return false;
     }
 
+    api::HttpResponse groupsResponse =
+        api::httpGet(api::PATH_GROUPS);
+    if (!groupsResponse.transportOk ||
+        groupsResponse.status < 200 || groupsResponse.status >= 300) {
+        return false;
+    }
+
     std::vector<radiantwave::db::ProclamationRecord> proclamations;
     std::vector<radiantwave::db::ProclamationCategoryRecord> categories;
+    std::vector<radiantwave::db::ProclamationGroupRecord> groups;
     if (!parseProclamationsJson(proclamationsResponse.body, proclamations) ||
-        !parseCategoriesJson(categoriesResponse.body, categories)) {
+        !parseCategoriesJson(categoriesResponse.body, categories) ||
+        !parseGroupsJson(groupsResponse.body, groups)) {
         return false;
     }
 
     if (!db.replaceCategories(categories)) {
         return false;
     }
+    if (!db.replaceGroups(groups)) {
+        return false;
+    }
     if (!db.syncProclamations(proclamations, defaultProclamationId)) {
         return false;
     }