For Vietnamese the preedit is the map key ('as', 'oong'); only the popup
and the commit path looked it up. Clients with inline preedit therefore
showed 'as' while Enter committed 'á'. impre() now maps once for every
reader, and snapshot() no longer maps a second time.
The hash map served a single exact-match lookup that the trie already
answers, at the price of a second container, a second file loader with
its own drift, and a Str-to-UTF-8 conversion on every chain probe. The
files are small (kanji.dict is 7.5k lines), so the trie holds both.
trieopen validates keys and each space-separated value word against Str
and reports path:line; trielookup takes the Str every caller holds and
treats a nil trie as an unloaded map; trienew/trieput exist for tests.
The overflow guards on growth, Trie.root (always 0) and the per-language
init loop written twice are gone.
Avoid reading inactive Str storage when deciding whether to publish a redraw. Keep the focused engine suite compact by retaining one case for each page, navigation, and empty-result invariant.
Add table-driven dictionary miss and language-switch state coverage, regress stale candidates after backspace, and clear them before dictionary refresh. Keep IPC and runtime-created file checks outside the unit runner.
