Greptile Summary

This PR adds a check for partial NO_REPLY tokens during streaming to prevent them from being displayed to users. The fix adds isSilentReplyPrefixText validation in the emitChatDelta function, which suppresses partial tokens like "NO_", "NO_R", "NO_RE", etc. that arrive before the complete "NO_REPLY" token.

Key changes:

• Added import for isSilentReplyPrefixText from the tokens module
• Added prefix check after the existing full token check (lines 298-301)
• The check prevents partial silent token prefixes from being emitted as chat deltas during streaming

Implementation correctness:

• The fix follows the same pattern already used in typing.ts, agent-runner-execution.ts, and streaming-directives.ts
• The order of checks is correct: full token check first, then prefix check
• The isSilentReplyPrefixText function is well-tested and requires an underscore to avoid false positives with natural language (e.g., "NO" or "No" won't be suppressed)

Testing:

• All 15 existing tests pass
• The isSilentReplyPrefixText function has comprehensive test coverage in tokens.test.ts

Confidence Score: 5/5

• This PR is safe to merge with no identified risks
• The change is minimal (4 lines), well-scoped, and follows an established pattern used consistently across the codebase. The function being used is already tested and proven in production use elsewhere. No logical errors, security issues, or breaking changes identified.
• No files require special attention

_{Last reviewed commit: 14de324}

Closing as superseded by merged #32183 and already-landed streaming lead-fragment fix #32116 for the NO_REPLY leak family.