docs: design native TurboQuant proximity accelerator

[forhappy]

Summary

• define a Prolly-native TurboQuant proximity accelerator without a Turbovec dependency
• specify deterministic transform, codebook, persistence, planning, async, proof, catalog, composite, and binding integration
• provide phased delivery with explicit correctness, recall, resource, performance, and release acceptance gates
• separate forced-backend GA from Auto qualification and gate QJL as a later extension

Validation

• git diff --cached --check
• verified balanced Markdown code fences and no duplicate headings
• documentation-only change; production tests were not run