review: fix P2 findings from codex pre-merge review

Final codex review surfaced two P2s that would break upgrades and
downstream salience.

1. install.sh:148 / install.ps1 — the top-level `.agent/` copy is
   skipped when the target already has one (line 39-42 / 45-48). So
   on an upgrade install of an older agentic-stack project, the pi
   extension's `memory-hook.ts` gets dropped, but the Python hook it
   invokes (`.agent/harness/hooks/pi_post_tool.py`) never arrives.
   Every `tool_result` then fires `missing-hook` forever. Fix: sync
   `pi_post_tool.py` explicitly in the pi case, both installers.

2. pi_post_tool.py:152 — `_emit_malformed()` was writing
   `importance="medium"` (string). Downstream `salience_score()` does
   `importance / 10.0`, which raises TypeError on a string and would
   crash context_budget.py, show.py, and auto_dream.py readers of
   AGENT_LEARNINGS.jsonl. Fix: use int 5 (middle of the 1-10 scale).

Smoke-tested:
- empty payload → entry has `importance: 5` (int), salience_score
  runs to 1.000 without error
- upgrade install on a project with old .agent/ (no pi_post_tool.py)
  → "synced for upgrades" line fires, file now present

Author: codejunkie99

.agent/harness/hooks/pi_post_tool.py

@@ -143,13 +143,16 @@ def _emit_malformed(reason: str, raw_excerpt: str) -> None:
     JSON, this surfaces in AGENT_LEARNINGS.jsonl as a real signal.
     """
     excerpt = raw_excerpt[:200] if isinstance(raw_excerpt, str) else ""
+    # importance MUST be numeric — downstream salience_score() does
+    # `importance / 10.0` and a string would crash context_budget,
+    # show.py, and auto_dream readers. 5 ≈ "medium" on the 1-10 scale.
     on_failure(
         skill_name="pi",
         action="hook:malformed_payload",
         error=f"pi tool_result payload malformed: {reason}",
         context=excerpt,
         confidence=0.95,
-        importance="medium",
+        importance=5,
         pain_score=2,
     )
 

install.ps1

@@ -182,6 +182,13 @@ switch ($Adapter) {
         New-Item -ItemType Directory -Path $extensionsDir -Force | Out-Null
         Copy-Item (Join-Path $Src 'memory-hook.ts') (Join-Path $extensionsDir 'memory-hook.ts') -Force
         Write-Host "  + .pi/extensions/memory-hook.ts"
+        # Upgrade path: the .agent copy higher up is skipped when .agent
+        # already exists, but the pi extension calls this python hook,
+        # so sync it explicitly.
+        $hooksDir = Join-Path $TargetAgent 'harness/hooks'
+        New-Item -ItemType Directory -Path $hooksDir -Force | Out-Null
+        Copy-Item (Join-Path $Here '.agent/harness/hooks/pi_post_tool.py') (Join-Path $hooksDir 'pi_post_tool.py') -Force
+        Write-Host "  + .agent/harness/hooks/pi_post_tool.py (synced for upgrades)"
     }
     'standalone-python' {
         Copy-Item (Join-Path $Src 'run.py') (Join-Path $TargetDir 'run.py') -Force

install.sh

@@ -147,6 +147,13 @@ case "$ADAPTER" in
     mkdir -p "$TARGET/.pi/extensions"
     cp "$SRC/memory-hook.ts" "$TARGET/.pi/extensions/memory-hook.ts"
     echo "  + .pi/extensions/memory-hook.ts"
+    # Upgrade path: the top-level `.agent/` copy at line 39-42 is skipped
+    # when .agent already exists, but the pi extension calls this python
+    # hook, so sync it explicitly for installs on older agentic-stack
+    # projects that don't already have it.
+    mkdir -p "$TARGET/.agent/harness/hooks"
+    cp "$HERE/.agent/harness/hooks/pi_post_tool.py" "$TARGET/.agent/harness/hooks/pi_post_tool.py"
+    echo "  + .agent/harness/hooks/pi_post_tool.py (synced for upgrades)"
     ;;
   standalone-python)
     cp "$SRC/run.py" "$TARGET/run.py"