feat: telemetry data integrity — source tagging, UUID fingerprint, duration guards

- Add source field (live/test/dev) to telemetry pipeline: --source flag in
  gstack-telemetry-log, GSTACK_TELEMETRY_SOURCE env fallback, pass-through
  in telemetry-sync, source=eq.live filter on all dashboard queries
- Replace SHA-256 installation_id with UUID install_fingerprint for all tiers
  (not just community). Expand-contract migration: ADD new column + trigger
  to copy installation_id, preserving backward compat with old clients
- Fix duration bug: persist _TEL_START to file via $PPID (stable across bash
  blocks), cap durations at 86400s, reject negative values
- Ungate update-check pings from telemetry=off — sends only version + OS +
  random UUID. Generate .install-id in update-check for telemetry=off users
- Migration 003: source columns, install_fingerprint, duration CHECK
  constraint, indexes, recreated views with source filter, growth funnel
  (first-seen based), materialized views for daily installs + version adoption
- E2E test isolation: session-runner sets GSTACK_TELEMETRY_SOURCE=test
- 8 new telemetry tests (source field, duration caps, fingerprint persistence)

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

bin/gstack-telemetry-log

@@ -35,6 +35,7 @@ ERROR_CLASS=""
 ERROR_MESSAGE=""
 FAILED_STEP=""
 EVENT_TYPE="skill_run"
+SOURCE=""
 
 while [ $# -gt 0 ]; do
   case "$1" in
@@ -47,10 +48,14 @@ while [ $# -gt 0 ]; do
     --error-message) ERROR_MESSAGE="$2"; shift 2 ;;
     --failed-step)   FAILED_STEP="$2"; shift 2 ;;
     --event-type)    EVENT_TYPE="$2"; shift 2 ;;
+    --source)        SOURCE="$2"; shift 2 ;;
     *) shift ;;
   esac
 done
 
+# Source: flag > env > default 'live'
+SOURCE="${SOURCE:-${GSTACK_TELEMETRY_SOURCE:-live}}"
+
 # ─── Read telemetry tier ─────────────────────────────────────
 TIER="$("$CONFIG_CMD" get telemetry 2>/dev/null || true)"
 TIER="${TIER:-off}"
@@ -109,19 +114,19 @@ if [ -d "$STATE_DIR/sessions" ]; then
   [ -n "$_SC" ] && [ "$_SC" -gt 0 ] 2>/dev/null && SESSIONS="$_SC"
 fi
 
-# Generate installation_id for community tier
-INSTALL_ID=""
-if [ "$TIER" = "community" ]; then
-  HOST="$(hostname 2>/dev/null || echo "unknown")"
-  USER="$(whoami 2>/dev/null || echo "unknown")"
-  if command -v shasum >/dev/null 2>&1; then
-    INSTALL_ID="$(printf '%s-%s' "$HOST" "$USER" | shasum -a 256 | awk '{print $1}')"
-  elif command -v sha256sum >/dev/null 2>&1; then
-    INSTALL_ID="$(printf '%s-%s' "$HOST" "$USER" | sha256sum | awk '{print $1}')"
-  elif command -v openssl >/dev/null 2>&1; then
-    INSTALL_ID="$(printf '%s-%s' "$HOST" "$USER" | openssl dgst -sha256 | awk '{print $NF}')"
+# Generate/read persistent UUID fingerprint (all tiers, not just community)
+INSTALL_FP=""
+FP_FILE="$STATE_DIR/.install-id"
+if [ -f "$FP_FILE" ]; then
+  INSTALL_FP="$(cat "$FP_FILE" 2>/dev/null | tr -d '[:space:]')"
+fi
+if [ -z "$INSTALL_FP" ]; then
+  INSTALL_FP="$(uuidgen 2>/dev/null || cat /proc/sys/kernel/random/uuid 2>/dev/null || python3 -c 'import uuid; print(uuid.uuid4())' 2>/dev/null || echo "")"
+  INSTALL_FP="$(echo "$INSTALL_FP" | tr '[:upper:]' '[:lower:]')"  # normalize case
+  if [ -n "$INSTALL_FP" ]; then
+    mkdir -p "$STATE_DIR"
+    echo "$INSTALL_FP" > "$FP_FILE"
   fi
-  # If no SHA-256 command available, install_id stays empty
 fi
 
 # Local-only fields (never sent remotely)
@@ -145,20 +150,28 @@ ERR_MSG_FIELD="null"
 STEP_FIELD="null"
 [ -n "$FAILED_STEP" ] && STEP_FIELD="\"$(echo "$FAILED_STEP" | head -c 30)\""
 
+# Cap unreasonable durations
+if [ -n "$DURATION" ] && [ "$DURATION" -gt 86400 ] 2>/dev/null; then
+  DURATION=""  # null if > 24h
+fi
+if [ -n "$DURATION" ] && [ "$DURATION" -lt 0 ] 2>/dev/null; then
+  DURATION=""  # null if negative
+fi
+
 DUR_FIELD="null"
 [ -n "$DURATION" ] && DUR_FIELD="$DURATION"
 
 INSTALL_FIELD="null"
-[ -n "$INSTALL_ID" ] && INSTALL_FIELD="\"$INSTALL_ID\""
+[ -n "$INSTALL_FP" ] && INSTALL_FIELD="\"$INSTALL_FP\""
 
 BROWSE_BOOL="false"
 [ "$USED_BROWSE" = "true" ] && BROWSE_BOOL="true"
 
-printf '{"v":1,"ts":"%s","event_type":"%s","skill":"%s","session_id":"%s","gstack_version":"%s","os":"%s","arch":"%s","duration_s":%s,"outcome":"%s","error_class":%s,"error_message":%s,"failed_step":%s,"used_browse":%s,"sessions":%s,"installation_id":%s,"_repo_slug":"%s","_branch":"%s"}\n' \
+printf '{"v":1,"ts":"%s","event_type":"%s","skill":"%s","session_id":"%s","gstack_version":"%s","os":"%s","arch":"%s","duration_s":%s,"outcome":"%s","error_class":%s,"error_message":%s,"failed_step":%s,"used_browse":%s,"sessions":%s,"install_fingerprint":%s,"source":"%s","_repo_slug":"%s","_branch":"%s"}\n' \
   "$TS" "$EVENT_TYPE" "$SKILL" "$SESSION_ID" "$GSTACK_VERSION" "$OS" "$ARCH" \
   "$DUR_FIELD" "$OUTCOME" "$ERR_FIELD" "$ERR_MSG_FIELD" "$STEP_FIELD" \
   "$BROWSE_BOOL" "${SESSIONS:-1}" \
-  "$INSTALL_FIELD" "$REPO_SLUG" "$BRANCH" >> "$JSONL_FILE" 2>/dev/null || true
+  "$INSTALL_FIELD" "$SOURCE" "$REPO_SLUG" "$BRANCH" >> "$JSONL_FILE" 2>/dev/null || true
 
 # ─── Trigger sync if tier is not off ─────────────────────────
 SYNC_CMD="$GSTACK_DIR/bin/gstack-telemetry-sync"