[FEATURE] Queue context without triggering computation

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

When nearing a usage limit, I want to add context or notes for Claude Code to reference in the next session without consuming tokens. Currently, any input triggers a model invocation, which I can't afford when approaching limits.

Proposed Solution

A mechanism to enqueue context that:

• Gets stored in the conversation/session
• Does not trigger a model invocation or token consumption
• Is available and acknowledged when the next actual prompt (requiring computation) is sent
• Survives context compaction
• Can still be edited like a queued prompt would

Possible implementations:

• A /store <text> or /reserve <text> (probably not /enqueue <text> command that saves to context without invoking the model
• A way to append to a context buffer that gets automatically prepended to the next prompt
• A "dry mode" for certain commands that loads context but doesn't process/respond

Alternative Solutions

Currently I work around this by keeping the context unsubmitted. If the terminal closes, or worse, my machine crashes, the context is lost.

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

[Edited to a more specific example.]

The Scenario:

1. I'm mid-session refactoring auth. I discover: "Edge case—business_id null silently fails validation"
2. I have ~10% of my budget left before hitting my rate limit
3. I want to context-switch to a different project/session that I've been meaning to work on
4. I'd rather spend those last 10% tokens on the other session than on continuing auth

Current behavior: I can't save the edge case discovery without consuming tokens (either by queuing it or sending it directly). So I either:

• Lose the context (risky; might forget or re-discover later)
• Burn tokens now to save it (defeats the purpose—wastes budget I wanted to allocate elsewhere)

With /store:

• /store Edge case: business_id null fails validation silently—needs handling
• Zero tokens consumed; context persists to the session
• I context-switch to the other project with my remaining budget intact
• When I return to auth (with fresh budget), the discovery is there

Why this matters: It lets me be strategic about token allocation across multiple projects when I'm rate-limited.

Additional Context

• Currently use /queue to defer prompts, but this still triggers computation when executed
• Similar to how interrupt-and-steer works (accepts input mid-turn), but in the opposite direction: accept context before the turn starts
• Valuable for rate-limited workflows and long sessions where context needs to accumulate

Related Issues

• #63190 – Deferred messages (queuing prompts for later execution, but assumes computation will happen)
• #49373 – End-of-turn queue mode (preventing mid-task injection, but still triggers compute)

How this differs: This request is specifically about storing context without any token consumption, whereas the related issues focus on when queued prompts execute.