Empty SSE Events Leak Through Opencode Stream Processor #2840

• Summary: The shared SSE client in opencode/packages/sdk/js/src/gen/core/serverSentEvents.gen.ts emits an event for every data: stanza, even if the
  payload is empty/whitespace. Downstream code receives meaningless events, forcing consumers (e.g., the Gemini plugin) to filter them manually.
• Impact: Plugins/tools that listen to streamed deltas must implement custom guards to avoid processing blank events. This leads to duplicated logic,
  brittle handling of real "" payloads, and wasted work for every SSE consumer.

This is visible when working with Gemini CLI OAauth

Propsed fix

opencode/packages/sdk/js/src/gen/core/serverSentEvents.gen.ts (+3 -0)
    155                    const rawData = dataLines.join("\n")
    156   +                if (!rawData.trim()) {
    157   +                  continue
    158   +                }
    159                    try {