fix: address review — scratch file survives crash, cap read size, fix instruction (#262)

- Remove SCRATCH_FILE from action-agent cleanup() trap so it survives crashes
- Change instruction to note contents already injected (avoid wasted tool call)
- Cap scratch file read at 8KB via head -c 8192
- Move predictor scratch instruction after formula (consistent placement)
- Remove redundant FINAL_PHASE re-reads in planner/predictor

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

action/action-agent.sh

@@ -88,7 +88,7 @@ cleanup() {
   agent_kill_session "$SESSION_NAME"
   # Best-effort docker cleanup for containers started during this action
   (cd "${PROJECT_REPO_ROOT}" 2>/dev/null && docker compose down 2>/dev/null) || true
-  rm -f "$PHASE_FILE" "$IMPL_SUMMARY_FILE" "$PREFLIGHT_RESULT" "$SCRATCH_FILE"
+  rm -f "$PHASE_FILE" "$IMPL_SUMMARY_FILE" "$PREFLIGHT_RESULT"
 }
 trap cleanup EXIT
 

lib/formula-session.sh

@@ -142,7 +142,7 @@ Periodically (every 10-15 tool calls), write a summary of:
 - What remains to do
 to: ${scratch_file}
 
-If you find this file exists when you start, read it first — it is your previous context.
+If this file existed at session start, its contents have already been injected into your prompt above.
 This file is ephemeral — not evidence or permanent memory, just a compaction survival mechanism.
 _SCRATCH_EOF_
 }
@@ -153,7 +153,7 @@ _SCRATCH_EOF_
 read_scratch_context() {
   local scratch_file="$1"
   if [ -f "$scratch_file" ]; then
-    printf '## Previous context (from scratch file)\n%s\n' "$(cat "$scratch_file")"
+    printf '## Previous context (from scratch file)\n%s\n' "$(head -c 8192 "$scratch_file")"
   fi
 }
 

planner/planner-run.sh

@@ -85,7 +85,7 @@ export CLAUDE_MODEL="opus"
 run_formula_and_monitor "planner"
 
 # ── Cleanup scratch file on normal exit ──────────────────────────────────
-FINAL_PHASE=$(read_phase "$PHASE_FILE")
-if [ "$FINAL_PHASE" = "PHASE:done" ]; then
+# FINAL_PHASE already set by run_formula_and_monitor
+if [ "${FINAL_PHASE:-}" = "PHASE:done" ]; then
   rm -f "$SCRATCH_FILE"
 fi

predictor/predictor-run.sh

@@ -64,12 +64,11 @@ about CI health, issue staleness, agent status, and system conditions.
 
 ## Project context
 ${CONTEXT_BLOCK}
-${SCRATCH_CONTEXT:+${SCRATCH_CONTEXT}
-}${SCRATCH_INSTRUCTION}
-
+${SCRATCH_CONTEXT}
 ## Formula
 ${FORMULA_CONTENT}
 
+${SCRATCH_INSTRUCTION}
 ${PROMPT_FOOTER}"
 
 # ── Run session ──────────────────────────────────────────────────────────
@@ -77,7 +76,7 @@ export CLAUDE_MODEL="sonnet"
 run_formula_and_monitor "predictor"
 
 # ── Cleanup scratch file on normal exit ──────────────────────────────────
-FINAL_PHASE=$(read_phase "$PHASE_FILE")
-if [ "$FINAL_PHASE" = "PHASE:done" ]; then
+# FINAL_PHASE already set by run_formula_and_monitor
+if [ "${FINAL_PHASE:-}" = "PHASE:done" ]; then
   rm -f "$SCRATCH_FILE"
 fi