Card accuracy pass 2: remove unmeasured speed claims, honest brand labels

Card accuracy sweep: honest brand labeling, remove dead links, upstream KV tip

docs: upstream-first KV-cache guidance (q8_0/q4_0, mainline Hadamard rotation); fork demoted to experimental

chore(card): add hardware compatibility section

chore(card): enrich YAML frontmatter (pipeline_tag, language, library_name, inference)

Add MLX quantized model

initial commit