highlight() used Promise.race with a 10s timeout, but the losing
semantic phase promise continued running 25 WASM micro-batches,
saturating the event loop and degrading all subsequent operations
(find() going from ~200ms to ~10,000ms).
Add AbortController to highlight() so the semantic phase stops
immediately on timeout or error. Pass abort signal through
embedBatch() → EmbeddingManager → micro-batch loop.
Also add defensive hardening:
- CandleEmbeddingEngine: try/catch around WASM calls resets engine
state on failure so next call triggers re-initialization
- WASMEmbeddingEngine: initialize() now checks underlying Candle
engine state, not just its own flag, completing the recovery chain
David Snelling
f8dd93c93c