/context command ignores CLAUDE_AUTOCOMPACT_PCT_OVERRIDE when displaying buffer size

Bug Description

The /context command always displays the default autocompact buffer size (~33K tokens at 200K context), even when CLAUDE_AUTOCOMPACT_PCT_OVERRIDE is set. The env var correctly affects the actual autocompact trigger, but the display is wrong.

Environment

• Claude Code: v2.1.49
• Platform: macOS (Apple Silicon)
• Context window: 200K

Reproduction Steps

1. Set CLAUDE_AUTOCOMPACT_PCT_OVERRIDE=70 in settings or environment
2. Start a session
3. Run /context
4. Observe the "Autocompact buffer" shows ~33K (16.5%) — the default value
5. Expected: should show ~74K (37%) reflecting the 70% override

Root Cause (from source analysis)

Two separate code paths calculate the autocompact threshold:

1. Actual trigger logic — CORRECT

The function that decides when to fire autocompact reads CLAUDE_AUTOCOMPACT_PCT_OVERRIDE and computes:

threshold = min(floor(effectiveWindow * PCT/100), effectiveWindow - 13000)

With PCT=70 and 200K context: min(floor(180,000 * 0.70), 167,000) = 126,000 tokens

2. /context display logic — BUG

The display function computes:

displayThreshold = effectiveWindow - 13000  // always uses default, ignores env var
buffer = maxContext - displayThreshold       // = 33,000

This never calls the function that reads CLAUDE_AUTOCOMPACT_PCT_OVERRIDE. It hardcodes the default formula.

Impact

| Metric | /context shows | Actual behavior |
|---|---|---|
| Autocompact buffer | 33K (16.5%) | 74K (37%) |
| Trigger point | ~167K tokens | ~126K tokens |
| Free space | Inflated | Smaller than displayed |

Users relying on /context to judge remaining capacity will overestimate how much space they have before autocompact fires.

Suggested Fix

In the display function, replace the hardcoded default calculation with a call to the same threshold function used by the actual trigger logic, so both paths use the same formula that respects the env var override.

Related Issues

• #24828 — requests extending CLAUDE_AUTOCOMPACT_PCT_OVERRIDE to the main conversation (it may already work for the trigger; this issue is about the display)
• #27037 — documents CLAUDE_AUTOCOMPACT_PCT_OVERRIDE behavior from reverse engineering