feat(ble): expose isInitialized and reclaim memory before radios start

The controller and the WiFi driver each need a large aggregate allocation,
which a live app sitting on garbage can deny - that is why a failed connect
often succeeded on retry. Both bindings now collect before initializing, and
the tree reserves its node and spec capacity so a build does not reallocate
into a tight heap.

lua/api/core/ble.lua

@@ -19,6 +19,10 @@ function ble.init(name) end
 ---Stops the BLE stack and releases its memory.
 function ble.deinit() end
 
+---Whether the BLE stack is running.
+---@return boolean
+function ble.isInitialized() end
+
 ---Scans for advertising devices.
 ---@param durationMs? integer Defaults to 3000.
 ---@return BleDevice[]? devices