wasm: rebuild with streaming quant_generate + quant_free_string

Rebuilt quant.wasm with emcc 5.0.5. Key changes from C source:
  - quant_ask → quant_generate with on_token callback (streaming)
  - free(result) → quant_free_string(result) (cross-heap safety)
  - context_length + k_highres_window fields in quant_config
  - infinite scrollback (context shift on overflow)

Binary: quant.wasm 193 KB, quant.js 64 KB.

Tokens now stream to the browser as they're generated instead of
appearing all at once after the full response completes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: unamedkr