data: one trie for maps and dictionaries, one loader

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.

Makefile

@@ -19,7 +19,7 @@ DOCKER_IMAGE = strans-build
 DOCKER_RUN = docker run --rm --user "$$(id -u):$$(id -g)" \
 	-v "$(CURDIR):/src" $(DOCKER_IMAGE)
 
-SRCS = dict.c font.c hash.c ibus.c ipc.c ko.c main.c popup_layout.c \
+SRCS = dict.c font.c ibus.c ipc.c ko.c main.c popup_layout.c \
 	srv.c str.c strans.c trie.c vi.c win.c
 XIMSRCS = xim/xim.c xim/keymap.c xim/ximtext.c
 XIMOBJS = $(XIMSRCS:.c=.o)