TTS stops narrating last pre-tool sentence when Claude starts tool use

[rosscado]

When Claude launches one of its tool cards (e.g., computer use), SayPi’s TTS stream stops speaking a few words before the tool block appears. Once the tool completes, TTS resumes—but it jumps in mid-sentence rather than continuing seamlessly. The stop/start happens even though the final sentence before the tool is present in the DOM and is delivered to /speak/{uuid}/stream as a normal chunk.

Steps to Reproduce

1. In Claude, prompt it to “show me the computer use tool” (or any request that triggers the computer/tool panel).
2. Let the assistant respond while SayPi TTS is streaming.
3. Listen as the narration approaches the tool preamble (e.g., “Sure! Here’s a quick demo. I’ll create a simple Python script and run it:”).
4. Observe that audio stops before the tool card renders, then resumes only after the tool finishes (starting with the next sentence or bullet list).

Observed Behaviour

• Audio playback halts at “…I’ll create a simple Python script” (or similar) just before the tool card shows up.
• Once the tool completes, audio playback resumes where it left off with “…and run it:”, before proceeding to the next paragraph.
• Client logs confirm chunk seq=3 (47 chars, the full sentence) is sent before tool start, yet the audio for that chunk isn’t heard until after the tool run.
• Example log snippet:

[saypi] Detected Claude tool use start …
[TTS KeepAlive] Starting keep-alive for f39f2389…
TextToSpeechService: Sending chunk seq=3 uuid=f39f2389… length=47
…
[saypi] Detected Claude tool use end …
TextToSpeechService: Sending chunk seq=4 uuid=f39f2389… length=323

Server side confirms chunk index 3 (“I’ll create a simple Python script and run it:”) is received at 10:16:09 and processed normally.

Expected Behaviour

TTS should continue speaking every chunk in order, right up to the tool card; it should not stop speaking mid-sentence before tool execution begins.

Notes

• Keep-alive behaviour looks normal (only a couple of PUTs from the client); the large number of “Keep-alive signal received” entries is server logging.
• Happens consistently when Claude renders any tool card, though the precise moment it pauses can move around, sometimes even stopping mid-word; not introduced by the recent keep-alive/indicator changes.