Handle telemetry in non-interactive mode (#1002)

Changes:
- Ensure proper shutdown in non-interactive mode
- Ensures the initial user prompt is logged in non-interactive mode
- Improve telemetry for streaming - handle chunks and input token count is now alongside other token counts in response

To test:
- Follow instructions in https://github.com/google-gemini/gemini-cli/blob/main/docs/core/telemetry.md#google-cloud
- Run CLI in non-interactive mode and observe logs/metrics in GCP Logs Explorer and Metrics Explorer

#750

packages/cli/src/gemini.tsx

@@ -33,6 +33,7 @@ import {
   WebSearchTool,
   WriteFileTool,
   sessionId,
+  logUserPrompt,
 } from '@gemini-cli/core';
 
 export async function main() {
@@ -120,6 +121,11 @@ export async function main() {
     process.exit(1);
   }
 
+  logUserPrompt(config, {
+    prompt: input,
+    prompt_length: input.length,
+  });
+
   // Non-interactive mode handled by runNonInteractive
   const nonInteractiveConfig = await loadNonInteractiveConfig(
     config,