Release v4.1 — Optimized AI Translation Pipelines · Meapri/EdgeTranslate-v3

What's New in v4.1

Single-pass streaming — Removed the redundant 2nd-pass refinement logic that added latency without meaningful quality improvement. Translations now stream in a single pass for significantly faster response times.
Smart text chunking — Long inputs are intelligently split at paragraph → line → sentence boundaries (800-char optimal window) to maintain formatting and translation quality.
Proper noun protection — System prompt now explicitly forbids hallucination and improper substitution of proper nouns, brands, and titles (e.g. 「はじまりのピカチュウ」 no longer gets replaced with random movie titles).
Post-translation safety net — Known false-friend corrections (e.g. 国勢調査 → 인구총조사, not 국세조사) applied as a final pass.
Passthrough punctuation — Decorative symbols (※, →, ★, ●, etc.) are preserved through translation via placeholder substitution.

Prompt optimization — Reduced prompt token count by ~50% while maintaining translation quality. Removed verbose script rules, redundant instructions, and unnecessary role declarations.
Generation config — Removed redundant candidateCount and topK parameters; thinkingBudget: 0 for maximum throughput.
Script constraints — Simplified from 22-language verbose rules to 9-language concise constraints.

Fixed mainMeaning field not receiving post-translation rules (e.g. 국세조사 correction only applied to translatedText, not mainMeaning).
Fixed originalText in chunked translations incorrectly set to the full input text instead of the current chunk.
Fixed parseInt calls missing radix parameter (ESLint warnings).
Fixed unnecessary arguments passed to buildGeminiNanoSystemPrompt() in the on-device bridge.

Removed ~250 lines of dead code across both pipelines: getPrimaryScript, getTargetLanguageOutputRule, findSoftBreak, splitLongParagraphAtSentenceEnds, splitTextIntoParagraphChunks, needsRefinement, and unused constants.
Extracted smartSplitText() as a shared utility function.
Unified prompt structure between chrome_builtin_translate.js and on_device_bridge.js.