feat(runtime): social layer — intent / templates / chat memory (Phase 5)

Phase 5 of plans/autonomous-survival-bot-prd.md. Make the bot feel
present in chat without ever becoming a command executor.

New: runtime/social/
- intent.js: classifyIntent({text, botName}) returns one of GREETING /
  STATUS_QUESTION / ADDRESSED_BANTER / COMMAND_LIKE / UNSAFE_REQUEST /
  AMBIENT. Unicode-aware word boundaries so cyrillic + latin both work
  ("Привет всем" → GREETING, "build me a tower" → AMBIENT unless
  addressed).
- reply.js: generateReply({intent, speaker, snapshot, diaryTail}) →
  short templated response, or {send: null, escalate: true} for the
  caller to decide whether to spend Pi tokens.
- memory.js: createChatMemory() — per-speaker LRU buffer of recent
  lines; redacts password / api_key / JWT-shaped tokens at append
  time, so the buffer can be safely fed back into any future prompt.
- social.test.js: 12 tests (intent edges, memory eviction, redaction,
  reply routing). npm test now 40/40.

state-store.js additions:
- readDiaryTail(n) — reads the last N lines of today's diary; used by
  status replies.
- writeEscalation({from, request, whyUnsure, wouldHave}) /
  listEscalations() — JSONL log under state/<host>/escalations.jsonl
  for UNSAFE_REQUEST classifications and future operator review.

bot.js: handleChat() now routes through social/intent + social/reply
(replacing the Phase-0 inline regexes), records every line into
chatMemory, and writes an escalation when classifyIntent returns
UNSAFE_REQUEST. Command-like notice + dialog-only behaviour from
Phase 0 are preserved.

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

package.json

@@ -16,7 +16,7 @@
     "tui": "tsx tui/tui.tsx",
     "propose:apply": "node scripts/propose-apply.js",
     "stop": "bash scripts/stop.sh",
-    "test": "node --test runtime/skills/contract.test.js runtime/skills/groups.test.js runtime/curriculum.test.js"
+    "test": "node --test runtime/skills/contract.test.js runtime/skills/groups.test.js runtime/curriculum.test.js runtime/social/social.test.js"
   },
   "dependencies": {
     "dotenv": "^16.4.5",