fix vietnamese telex: qu-/gi- onset tone placement and dd+tone

transvi fixes:

1. qu-/gi- onset tone placement. The u after q, and the i after g when a
   vowel follows, are onset glides rather than the rime nucleus, so the
   tone must skip them: qua -> quá (was qúa), gia -> giá. The onset was
   previously passed straight through to the app, so transvi never saw it
   and toned the glide. Keep the onset in the preedit by adding qu-/gi-
   clusters to telex.map (mktelex.py onsets(), appended additively to the
   curated map), and add onsetglide() so transvi skips the glide. gi- with
   no following vowel keeps i as the nucleus (gì, gìn).

2. A tone key on a vowel-less preedit (e.g. "đ" from dd) now commits the
   preedit and lets the tone key pass through (eat=0), matching the engine
   commit-on-passthrough invariant, instead of eating it into the commit.

Verified against the running engine: qua/quan/quay/quê/quên/quyển,
gia/già/giàu/giữ/giúp/giống, gì/gìn, dd+s; unchanged mua->mùa, của, lúa;
all non-qu/gi words byte-identical to before.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

map/mktelex.py

@@ -31,7 +31,10 @@ upper = str.maketrans(
 def addtone(v, t):
 	return v.translate(tone[t])
 
+entries = []
+
 def emit(input, output):
+	entries.append((input, output))
 	print(f"{input}\t{output}")
 	def up(s):
 		c = s[0].translate(upper)
@@ -147,6 +150,24 @@ def final():
 			for t in tone:
 				emit(i+c+t, o.replace(v, addtone(v, t), 1)+c)
 
+def onsets():
+	# Keep the qu-/gi- onset in the preedit so the tone lands on the rime
+	# nucleus, not on the onset glide (qua->quá not qúa, gia->giá not gía).
+	# transvi (onsetglide) knows to skip the glide; here we only need the
+	# composed clusters to exist so the preedit accumulates them.
+	vowels = set("aeiouy")
+	tones = set("sfrxj")
+	base = [(i, o) for (i, o) in list(entries)
+		if i and i[0] in vowels and not (set(i) & tones)]
+	for i, o in base:
+		if i[0] != 'u':		# no qu+u syllable; u is the glide
+			emit("qu" + i, "qu" + o)
+		emit("gi" + i, "gi" + o)
+	# gi- with the i as nucleus (no following vowel): gì, gìn, gìm, ...
+	for c in ["", "c", "m", "n", "p", "t", "ch", "ng", "nh"]:
+		if c:
+			emit("gi" + c, "gi" + c)
+
 vowel1()
 vowel2()
 vowel3()
@@ -157,3 +178,4 @@ tone1mod()
 tone2mod()
 escape()
 final()
+onsets()