feat(ralph): rate limit budget tracking + whatsapp text-keywords

Task #1 — Rate limit budget tracking MVP:
- tools/ralph_usage.py: pure functions (extract_usage_entry, parse_usage_jsonl,
  aggregate_by_day/_project, filter_by_days, summarize) + CLI append/summarize
  subcommands. Atomic write via temp+rename.
- tools/ralph/ralph.sh: după fiecare claude -p, append usage entry
  derivat din JSON envelope la <project>/scripts/ralph/usage.jsonl. Best-effort,
  niciodată blochează rularea (|| true).
- dashboard/handlers/ralph.py: GET /api/ralph/usage[?days=N] aggregează cross-
  project și returnează {today_cost, today_runs, by_project, by_day, ...}.

Task #2 — WhatsApp text-keyword commands:
- src/router.py: helper _translate_whatsapp_text mapează "aprob"/"stop <slug>"/
  "stare [<slug>]" → /a, /k, /l. Apelat DOAR pe adapter whatsapp în
  _try_ralph_dispatch (Discord/TG nu sunt afectate). NU acoperim propose
  intentionat — descrierea liberă e prea fragilă pentru parsing text-only.

Tests: 49 noi (test_ralph_usage 28 + test_whatsapp_keywords 21) + 4 noi în
test_dashboard_ralph_endpoint pentru /api/ralph/usage. Toate trec; regression
suite (test_router, test_router_planning, test_dashboard_ralph_endpoint,
test_whatsapp) — 90/90 pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/ralph/ralph.sh

@@ -39,6 +39,21 @@ else
   DAG_HELPER=""
 fi
 
+# Usage helper auto-detect (rate limit budget tracking — best effort, niciodată
+# blochează rularea Ralph dacă lipsește)
+if [ -n "$RALPH_USAGE_HELPER" ] && [ -f "$RALPH_USAGE_HELPER" ]; then
+  USAGE_HELPER="$RALPH_USAGE_HELPER"
+elif [ -f "/home/moltbot/echo-core/tools/ralph_usage.py" ]; then
+  USAGE_HELPER="/home/moltbot/echo-core/tools/ralph_usage.py"
+elif [ -f "/home/moltbot/echo-core-instr/tools/ralph_usage.py" ]; then
+  USAGE_HELPER="/home/moltbot/echo-core-instr/tools/ralph_usage.py"
+elif [ -f "$SCRIPT_DIR/ralph_usage.py" ]; then
+  USAGE_HELPER="$SCRIPT_DIR/ralph_usage.py"
+else
+  USAGE_HELPER=""
+fi
+USAGE_FILE="$SCRIPT_DIR/usage.jsonl"
+
 # Verifică că jq este instalat
 if ! command -v jq &> /dev/null; then
     echo "Eroare: jq nu este instalat. Rulează: apt install jq"
@@ -292,6 +307,15 @@ EOF
   set -e
   OUTPUT=$(cat "$LOG_FILE")
 
+  # Rate limit budget tracking (best-effort, never blocks Ralph)
+  if [ -n "$USAGE_HELPER" ]; then
+    "$RALPH_PYTHON" "$USAGE_HELPER" append \
+      "$USAGE_FILE" "$LOG_FILE" \
+      --slug "$PROJECT_NAME" \
+      --story-id "$CURRENT_STORY" \
+      --iter "$i" 2>/dev/null || true
+  fi
+
   # W3: rate limit detection (max 1 retry per rulare)
   if is_rate_limited "$OUTPUT" || [ "$CLAUDE_EXIT" = "29" ]; then
     if [ "$RATE_LIMIT_RETRY_USED" = "0" ]; then