feat(subscriptions): gestion des abonnements par groupes façon PocketTube

- Tables subscription_groups + subscription_group_members (migration + schema)
- API CRUD groupes, membres par groupe, groupes par abonnement
- Page Abonnements: onglets Groupes/Chaines, modale creation/edition (icone/couleur), assignation unitaire + lot, filtre par groupe + recherche
- Sidebar: section Groupes avec navigation directe (queryParams)
- i18n nav.groups FR/EN + 4 tests unitaires service

db/migrations/20260926_add_subscription_groups.sql

@@ -0,0 +1,28 @@
+BEGIN TRANSACTION;
+
+-- Groupes d'abonnements (façon PocketTube) : dossiers thématiques par utilisateur.
+CREATE TABLE IF NOT EXISTS subscription_groups (
+  id TEXT PRIMARY KEY,
+  user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  name TEXT NOT NULL,
+  color TEXT NOT NULL DEFAULT '#ef4444',
+  icon TEXT NOT NULL DEFAULT '📁',
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL,
+  UNIQUE(user_id, name)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sub_groups_user ON subscription_groups(user_id);
+
+-- Relation plusieurs-à-plusieurs : une chaîne (abonnement) dans plusieurs groupes.
+CREATE TABLE IF NOT EXISTS subscription_group_members (
+  group_id TEXT NOT NULL REFERENCES subscription_groups(id) ON DELETE CASCADE,
+  subscription_id INTEGER NOT NULL REFERENCES subscriptions(id) ON DELETE CASCADE,
+  added_at INTEGER NOT NULL,
+  PRIMARY KEY (group_id, subscription_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sub_group_members_sub ON subscription_group_members(subscription_id);
+CREATE INDEX IF NOT EXISTS idx_sub_group_members_group ON subscription_group_members(group_id);
+
+COMMIT;

db/schema.sql

@@ -109,6 +109,30 @@ CREATE TABLE IF NOT EXISTS subscriptions (
 
 CREATE INDEX IF NOT EXISTS idx_subs_user ON subscriptions(user_id);
 
+-- Groupes d'abonnements (façon PocketTube) -----------------------------------
+CREATE TABLE IF NOT EXISTS subscription_groups (
+  id TEXT PRIMARY KEY,
+  user_id TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  name TEXT NOT NULL,
+  color TEXT NOT NULL DEFAULT '#ef4444',
+  icon TEXT NOT NULL DEFAULT '📁',
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL,
+  UNIQUE(user_id, name)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sub_groups_user ON subscription_groups(user_id);
+
+CREATE TABLE IF NOT EXISTS subscription_group_members (
+  group_id TEXT NOT NULL REFERENCES subscription_groups(id) ON DELETE CASCADE,
+  subscription_id INTEGER NOT NULL REFERENCES subscriptions(id) ON DELETE CASCADE,
+  added_at INTEGER NOT NULL,
+  PRIMARY KEY (group_id, subscription_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sub_group_members_sub ON subscription_group_members(subscription_id);
+CREATE INDEX IF NOT EXISTS idx_sub_group_members_group ON subscription_group_members(group_id);
+
 -- Playlists -----------------------------------------------------------------
 CREATE TABLE IF NOT EXISTS playlists (
   id TEXT PRIMARY KEY,