Packaged WebBrain d1 adapter source

The d1-runtime.js source is copied byte-identically from the newly integrated
WebBrain module src/chrome/src/providers/d1-runtime.js. The new d1-preprocess.js
differs from the preserved old helper by two source-semantic corrections: present
null false/true criteria use Object.hasOwn (Python dict.get semantics) instead of
falling through to alternative no/yes keys, and finite small fractional JSON
numbers use Python-style exponent formatting. All other old helper bytes remain
exact. JavaScript cannot recover Python int versus integral-float distinctions;
preformatted state/criterion strings are the exact-lexical escape hatch.
The actual WebBrain project copyright/license notice (Copyright 2026 Emre Sokullu,
GPL-3.0-or-later) is retained at licenses/webbrain/LICENSE. No permissive license is
silently substituted for that project notice. Source is included, not remote code.

The model weights, ONNX graphs and upstream reference code retain their separate
LFM Open License v1.0 notices. ONNX Runtime retains MIT notices and Transformers.js
retains Apache-2.0 notices. Separate notices are not a legal compatibility opinion.
Owner/legal commercial and distribution eligibility determination is separate.

The runtime/vendor/transformers.web.js module has exactly two documented relative
import-linkage changes; see runtime/vendor/vendor-manifest.json. No model bytes,
calibration, tokenizer behavior or answer semantics are changed by packaging.