Resumed sessions repeatedly stop after partial execution and require manual continue prompts

## Update: still reproducible in 0.53.0

This is an unexpected failure in the `--resume` execution path, not a feature request or a general model-quality report.

- Reproduced on Gemini CLI 0.47.0 and 0.49.0.
- The task starts normally after resuming but stops before completion.
- No quota, context-window, or execution error is displayed.
- Entering `continue` resumes the same task temporarily, after which it may stop again.
- New sessions do not exhibit the same behavior as frequently.
- The issue occurs more frequently during long-running, multi-step coding tasks that require analyzing or modifying a large codebase and involve multiple tool executions.
- The separate session-file persistence and data-loss bug is tracked in #27368.

**Expected behavior:** A resumed session should continue executing the requested task until completion, or display an actionable error explaining why execution stopped.

---

### What happened?

When I resume an existing Gemini CLI session and ask it to continue the previous task, the model starts processing but frequently stops responding midway.

The issue appears as if reasoning or tool execution has been interrupted. No final response or explicit error message is displayed, and the session does not continue unless I terminate or restart the CLI.

This happens repeatedly with resumed sessions. New sessions appear to work more reliably.

### Steps to reproduce

1. Start Gemini CLI in a project directory.
2. Work on a long-running, multi-step coding task that requires analyzing or modifying a large codebase and involves multiple tool executions.
3. Exit Gemini CLI.
4. Resume the session using:
```bash
gemini --resume
```
5. Ask the model to continue the previous task.
6. Processing begins but may stop before producing a final response.

### Actual behavior

- The session is restored successfully.
- Reasoning or tool execution begins.
- The response stops midway without completion.
- No actionable error, quota warning, or context-limit message is shown.

### Screenshot

### What did you expect to happen?

The resumed session should restore the previous conversation context and complete the requested task normally.

If the session cannot continue because of a context-window, quota, session-size, or turn limit, Gemini CLI should display a clear error or status message with a recommended recovery action instead of silently stopping.

### Client information

Client Information

- Gemini CLI version: 0.47.0
- Operating system: macOS 26.5.1 (Build 25F80)
- Architecture: Apple Silicon
- Node.js version: v26.3.0
- Gemini CLI path: /opt/homebrew/bin/gemini
- Subscription: Gemini Code Assist Standard
- Account type: Organization account

The email address from `/about` has been intentionally omitted.

### Login information

Google Sign-In using an organization account with a Gemini Code Assist Standard license. I am not intentionally using a Gemini API key or Vertex AI authentication for this workflow.

### Anything else we need to know?

### Frequency

The issue occurs repeatedly with resumed sessions, but not on every attempt.

### Additional observations

- It is more noticeable in longer sessions with multiple tool executions.
- Starting a new session often avoids the problem.
- The session is resumed from the same project directory.
- No explicit quota, context-window, or session-limit error is displayed.
- The behavior appears related to restored session context rather than the original task.

This issue is also reproduced in 0.50.0...

This issue is also reproduced in 0.51.0...
This issue is also reproduced in 0.52.0...
This issue is also reproduced in 0.53.0...

Start by reproducing the failure with `gemini --resume ` during a long, multi-step task, then compare resumed and new sessions. Trace the resumed-session execution and tool-execution path to identify why processing stops without an error. Done means resumed tasks either complete normally or show an actionable recovery message.

Written by the indexing model from the issue text.