fix(bridge): keep decimals, versions and URLs whole in TTS sentence split

The streaming splitter treated every "." as a sentence boundary, so the
operational reply "17.5°C" was read as "17." / "5°C" and "1.8 km/h" as
"1." / "8 km/h" - numbers spoken digit-by-digit plus extra TTS calls.

An ASCII terminator (. ! ?) now only ends a sentence when it is followed by
whitespace, a closing quote/bracket, or end of text. In-token dots (decimals
"17.5", versions "v2.0", hosts "example.com") are followed by a digit/letter,
so they no longer split. CJK fullwidth terminators stay unconditional since
those scripts use no trailing space. Language-agnostic, punctuation only.

- bridge: lookahead-gated boundary regex + finditer-based chunking
- tests: regression cases for decimals (17.5/1.8), versions, URLs, and an
  integer that genuinely ends a sentence

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/test_bridge_sentence_split.py

@@ -75,3 +75,40 @@ def test_chunks_preserve_all_visible_content_in_order():
 def test_collapses_repeated_terminators_into_one_chunk():
     chunks = split_sentences("정말요?! 네 맞습니다.")
     assert chunks == ["정말요?!", "네 맞습니다."]
+
+
+@pytest.mark.unit
+def test_decimal_point_is_not_a_sentence_boundary():
+    # Regression: "17.5" / "1.8" used to split as "17." / "5" and "1." / "8",
+    # making the TTS read numbers digit-by-digit. The decimal dot is followed by
+    # a digit (no space), so it must stay inside one chunk.
+    assert split_sentences("현재 기온은 17.5도입니다.") == ["현재 기온은 17.5도입니다."]
+    assert split_sentences("바람은 1.8 km/h입니다.") == ["바람은 1.8 km/h입니다."]
+
+
+@pytest.mark.unit
+def test_decimals_across_two_sentences_split_only_at_the_real_end():
+    chunks = split_sentences("기온은 17.5도입니다. 바람은 1.8 km/h입니다.")
+    assert chunks == ["기온은 17.5도입니다.", "바람은 1.8 km/h입니다."]
+
+
+@pytest.mark.unit
+def test_english_decimal_and_version_numbers_stay_whole():
+    assert split_sentences("Pi is about 3.14 today.") == ["Pi is about 3.14 today."]
+    assert split_sentences("Upgrade to v2.0 now.") == ["Upgrade to v2.0 now."]
+
+
+@pytest.mark.unit
+def test_url_dots_are_not_boundaries():
+    # Dots inside a host/path are followed by letters, not whitespace, so the
+    # link is spoken in one piece; only the trailing sentence dot splits.
+    chunks = split_sentences("Visit example.com for details. Thanks!")
+    assert chunks == ["Visit example.com for details.", "Thanks!"]
+
+
+@pytest.mark.unit
+def test_integer_at_sentence_end_still_splits():
+    # A dot after a number that genuinely ends a sentence (followed by a space)
+    # is still a boundary - only the *internal* decimal dot is protected.
+    chunks = split_sentences("I scored 5. Next round now.")
+    assert chunks == ["I scored 5.", "Next round now."]