feat(workspaces): Store workspaces in a database

This commit introduces a new `ZenWorkspacesStorage` class to handle the persistence of workspaces in a database. The previous implementation used JSON files, but this approach brings several advantages, including:

- Improved performance and scalability
- Easier data management and synchronization
- Enhanced security and data integrity

This change removes the reliance on JSON files and streamlines workspace management, leading to a more robust and reliable system.

src/ZenWorkspacesStorage.mjs

@@ -0,0 +1,89 @@
+var ZenWorkspacesStorage = {
+  async init() {
+    console.log('ZenWorkspacesStorage: Initializing...');
+    await this._ensureTable();
+  },
+
+  async _ensureTable() {
+    await PlacesUtils.withConnectionWrapper("ZenWorkspacesStorage._ensureTable", async db => {
+      await db.execute(`
+        CREATE TABLE IF NOT EXISTS moz_workspaces (
+          id INTEGER PRIMARY KEY,
+          uuid TEXT UNIQUE NOT NULL,
+          name TEXT NOT NULL,
+          icon TEXT,
+          is_default INTEGER NOT NULL DEFAULT 0,
+          is_active INTEGER NOT NULL DEFAULT 0,
+          container_id INTEGER,
+          created_at INTEGER NOT NULL,
+          updated_at INTEGER NOT NULL
+        )
+      `);
+    });
+  },
+
+  async saveWorkspace(workspace) {
+    await PlacesUtils.withConnectionWrapper("ZenWorkspacesStorage.saveWorkspace", async db => {
+      const now = Date.now();
+      await db.executeCached(`
+        INSERT OR REPLACE INTO moz_workspaces (
+          uuid, name, icon, is_default, is_active, container_id, created_at, updated_at
+        ) VALUES (
+          :uuid, :name, :icon, :is_default, :is_active, :container_id, 
+          COALESCE((SELECT created_at FROM moz_workspaces WHERE uuid = :uuid), :now),
+          :now
+        )
+      `, {
+        uuid: workspace.uuid,
+        name: workspace.name,
+        icon: workspace.icon || null,
+        is_default: workspace.default ? 1 : 0,
+        is_active: workspace.used ? 1 : 0,
+        container_id: workspace.containerTabId || null,
+        now
+      });
+    });
+  },
+
+  async getWorkspaces() {
+    const db = await PlacesUtils.promiseDBConnection();
+    const rows = await db.execute(`
+      SELECT * FROM moz_workspaces ORDER BY created_at ASC
+    `);
+
+    return rows.map(row => ({
+      uuid: row.getResultByName("uuid"),
+      name: row.getResultByName("name"),
+      icon: row.getResultByName("icon"),
+      default: !!row.getResultByName("is_default"),
+      used: !!row.getResultByName("is_active"),
+      containerTabId: row.getResultByName("container_id")
+    }));
+  },
+
+  async removeWorkspace(uuid) {
+    await PlacesUtils.withConnectionWrapper("ZenWorkspacesStorage.removeWorkspace", async db => {
+      await db.execute(`
+        DELETE FROM moz_workspaces WHERE uuid = :uuid
+      `, { uuid });
+    });
+  },
+
+  async setActiveWorkspace(uuid) {
+    await PlacesUtils.withConnectionWrapper("ZenWorkspacesStorage.setActiveWorkspace", async db => {
+      await db.executeTransaction(async function() {
+        await db.execute(`UPDATE moz_workspaces SET is_active = 0`);
+        await db.execute(`UPDATE moz_workspaces SET is_active = 1 WHERE uuid = :uuid`, { uuid });
+      });
+    });
+  },
+
+  async setDefaultWorkspace(uuid) {
+    await PlacesUtils.withConnectionWrapper("ZenWorkspacesStorage.setDefaultWorkspace", async db => {
+      await db.executeTransaction(async function() {
+        await db.execute(`UPDATE moz_workspaces SET is_default = 0`);
+        await db.execute(`UPDATE moz_workspaces SET is_default = 1 WHERE uuid = :uuid`, { uuid });
+      });
+    });
+  }
+};