[Bug] Context Window Compaction Fails Despite Available Space

Bug Description
I have plenty of free space in this context window (6.8% free before the autocompact buffer) but I'm still seeing "conversation too long" messages that won't let me compact.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.0.13
• Feedback ID: 202821b9-ac8c-4048-a232-a417f4553d53

Errors

[{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"prompt is too long: 211314 tokens > 200000 maximum\"},\"request_id\":\"req_011CTygfLSq8o4LRCEqE3t6X\"}\n    at N4.generate (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:428:21403)\n    at oS.makeStatusError (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:573:2117)\n    at oS.makeRequest (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:573:5330)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async WwQ.SD1.model (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:19050)\n    at async SD1 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2485:39781)\n    at async WwQ (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:19204)\n    at async file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:13417\n    at async ll0 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:4415)\n    at async CB1 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:13387)","timestamp":"2025-10-10T14:35:16.784Z"},{"error":"Error: Conversation too long. Press esc twice to go up a few messages and try again.\n    at kg1 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1687:1553)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Object.call (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1687:7055)\n    at async Yv5 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2586:7180)\n    at async I6Q (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2586:5257)\n    at async CJ8 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2700:1045)\n    at async w61 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2694:2056)\n    at async Ts1 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2700:2485)\n    at async file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2706:30586\n    at async file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2689:4706","timestamp":"2025-10-10T14:35:16.787Z"},{"error":"Error: Error during compaction: Error: Conversation too long. Press esc twice to go up a few messages and try again.\n    at Object.call (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1688:189)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async Yv5 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2586:7180)\n    at async I6Q (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2586:5257)\n    at async CJ8 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2700:1045)\n    at async w61 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2694:2056)\n    at async Ts1 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2700:2485)\n    at async file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2706:30586\n    at async file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2689:4706","timestamp":"2025-10-10T14:35:16.787Z"},{"error":"Error: 400 {\"type\":\"error\",\"error\":{\"type\":\"invalid_request_error\",\"message\":\"prompt is too long: 211314 tokens > 200000 maximum\"},\"request_id\":\"req_011CTyggBQ9Wg54om88qzA4w\"}\n    at N4.generate (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:428:21403)\n    at oS.makeStatusError (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:573:2117)\n    at oS.makeRequest (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:573:5330)\n    at process.processTicksAndRejections (node:internal/process/task_queues:105:5)\n    at async WwQ.SD1.model (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:19050)\n    at async SD1 (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2485:39781)\n    at async WwQ (file:///Users/azim/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:3197:19204)\n    at async file

Note: Error logs were truncated.