feat(telemetry): add local agent efficiency metrics

shared/hooks/scripts/Record-Compact.ps1

@@ -2,7 +2,11 @@
 param()
 $root = Split-Path (Split-Path $PSScriptRoot -Parent) -Parent
 $stateDir = Join-Path $root '.ai-session'
-New-Item $stateDir -ItemType Directory -Force | Out-Null
-('{"event":"compact","timestamp":"' + (Get-Date).ToUniversalTime().ToString('o') + '"}') | Add-Content (Join-Path $stateDir 'telemetry.jsonl')
+if ($env:AI_CONFIG_TELEMETRY -ne '0') {
+    New-Item $stateDir -ItemType Directory -Force | Out-Null
+    $path = Join-Path $stateDir 'telemetry.jsonl'
+    ('{"event":"compact","timestamp":"' + (Get-Date).ToUniversalTime().ToString('o') + '"}') | Add-Content $path
+    if ((Get-Item $path).Length -gt 1048576) { Move-Item $path ($path + '.1') -Force }
+}
 & python (Join-Path $PSScriptRoot 'session-state.py') --hook
 exit $LASTEXITCODE

shared/hooks/scripts/record-compact.sh

@@ -1,6 +1,5 @@
 #!/usr/bin/env bash
 set -euo pipefail
 root=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/../.." && pwd)
-mkdir -p "$root/.ai-session"
-printf '{"event":"compact","timestamp":"%s"}\n' "$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> "$root/.ai-session/telemetry.jsonl"
+[ "${AI_CONFIG_TELEMETRY:-1}" = 0 ] || { mkdir -p "$root/.ai-session" && printf '{"event":"compact","timestamp":"%s"}\n' "$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> "$root/.ai-session/telemetry.jsonl"; [ "$(wc -c < "$root/.ai-session/telemetry.jsonl")" -le 1048576 ] || mv -f "$root/.ai-session/telemetry.jsonl" "$root/.ai-session/telemetry.jsonl.1"; }
 python3 "$root/hooks/scripts/session-state.py" --hook