fix: heap-allocate tinfl_decompressor to prevent stack overflow in renderDeflatedJson

[Copilot]

tinfl_decompress_mem_to_heap places a tinfl_decompressor struct (~34 KB) on the task stack. On constrained ESP32 tasks (e.g. a BLE receive task), this immediately overflows the stack, causing a Stack protection fault panic at the first call to renderDeflatedJson.

Changes

• src/FastJsonDL.cpp — Replaced the tinfl_decompress_mem_to_heap call with an inline decompression loop that:
  • mallocs tinfl_decompressor on the heap instead of the stack
  • Grows the output buffer via realloc in the same pattern as the original helper
  • Frees both allocations on all exit paths (success and error)

// Before — tinfl_decompressor lives on the task stack (~34 KB)
void* outBuf = tinfl_decompress_mem_to_heap(compressedData, compressedLen, &outLen, 0);

// After — decompressor state on the heap; same loop semantics
tinfl_decompressor* decomp = static_cast<tinfl_decompressor*>(malloc(sizeof(tinfl_decompressor)));
tinfl_init(decomp);
// ... incremental tinfl_decompress loop with realloc'd output buffer ...
free(decomp);

Stack usage of renderDeflatedJson drops from ~34 KB to a handful of pointer-sized locals.

[martinberlin]

Great implementation. Works as expected!
Added my own fork of Miniz since it was not prepared to be added as a component in ESP-IDF