dsh-word-learn: Word lookup, frequency-based grading, and FSRS review in DSH

dsh-word-learn is an English vocabulary learning plugin maintained by guicaiyue, designed for developers who use English as their working language. Unlike selection-based translation, which focuses on understanding the sentence, this plugin aims to help users remember the word. When an English word is selected within the DSH conversation body, a learning card appears locally, displaying phonetic symbols, definitions, morphological variations, frequency levels, native pronunciation, examples, and synonyms. The dictionary is a 14.4 MB ECDICT SQLite database that supports offline lookup, morphological lemmatization, and five frequency tiers, with code strings and numeric suffixes filtered out. Queried words are automatically added to the local vocabulary notebook, recording the original sentence, encounter count, and a five-dimensional ability profile. The learning page utilizes the FSRS-6 (ts-fsrs@6.0.0) scheduling algorithm, splitting each word into two tracks: recognizable and writable. By default, the two tracks follow independent spaced repetition schedules, featuring a remedial review loop, multiple-choice definitions, and next-day reviews. The frontend is primarily located in dist/client.js; the 22 data interfaces share a unified entry point, write operations are restricted to specific methods, and cross-site requests return 403 errors. The README does not provide a unified installation command, the user.db file is non-renewable, and the plugin runs with the privileges of the current DSH process, so source code and license must be checked before installation.