Greptile Summary

This PR fixes two related bugs in the Feishu typing indicator implementation that caused log spam and stuck emoji reactions. The changes improve error handling by removing silent console.log calls and instead propagating errors to structured handlers. Key improvements include:

• Removed internal try-catch blocks from addTypingIndicator and removeTypingIndicator, allowing errors to propagate to proper error handlers
• Added isFeishuMessageNotFoundError helper to detect Feishu error code 231003 (message deleted/expired)
• Introduced typingDisabled flag that stops retry attempts when message no longer exists, preventing log spam from keepalive ticks
• Added guard if (typingState?.reactionId) return to prevent keepalive from overwriting valid reaction IDs with null
• Fixed race condition by nulling typingState before awaiting removal in stop() callback
• Added comprehensive unit tests for the error detection helper

The implementation correctly handles the error propagation flow: addTypingIndicator/removeTypingIndicator throw → errors caught by SDK's typing callback wrapper → routed to onStartError/onStopError → handled appropriately (disable retries for 231003, log other errors). The solution is well-designed and addresses the root causes described in #27418.

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The changes are well-structured and address specific, documented bugs. The error handling refactor follows proper patterns by letting errors propagate to structured handlers rather than silent catches. The logic for preventing duplicate reactions and disabling retries on permanent failures is sound. Tests provide good coverage of the error detection helper. The changes are scoped to fixing the specific issues without introducing unnecessary refactoring.
• No files require special attention

_{Last reviewed commit: a1889d1}

PR #27525 is superseded by commit 32ee2f0:
32ee2f0

That landed the current Feishu typing loop-breaker path and is the canonical fix line on main.