[BUG] compaction causes AGENTS.md to be re-attached because extract() skips compacted Read results #31764

Description

After session compaction, the extract() function in instruction.ts skips tool results that were compacted (part.state.time.compacted). This means the system forgets which AGENTS.md/CLAUDE.md files were already loaded by Read tool calls, causing duplicate re-attachment of instruction files.

Root Cause

packages/opencode/src/session/instruction.ts:21-22:

if (part.type === "tool" && part.tool === "read" && part.state.status === "completed") {
  if (part.state.time.compacted) continue  // <-- this skips after compaction

When compaction summarizes old messages, the Read tool results are marked as compacted. The extract() function skips these, returning an empty set. The resolve() function then re-loads and re-attaches AGENTS.md files that were already loaded, causing:

1. Duplicate instructions in the AI context window
2. Wasted tokens
3. AGENTS.md being re-read multiple times across compaction boundaries

Steps to reproduce

1. Start a session with an AGENTS.md file in the project
2. The instruction file is loaded via system() at startup
3. Let the conversation grow long enough for compaction to trigger
4. After compaction, a new Read tool call triggers resolve()
5. The extract() function returns empty (compacted results skipped)
6. AGENTS.md is loaded again as a new instruction

OpenCode version

1.17.3