feat(zero): Zero notes — AI persona for @zeropostru daily posts

Adds character-driven AI-generated notes pipeline parallel to articles:
  - migration: zero_notes table (channel-scoped, status flow draft→approved→published)
  - services/zeroPrompt.js — 12 theme buckets, few-shots, anti-repeat by bucket,
    sha256 theme_hash for dedup
  - services/zeroNotes.js — generateDraft/approve/skip/edit/autoApproveOldDrafts
  - services/zeroNotesRunner.js — TG publication with multipart pose images,
    FOR UPDATE SKIP LOCKED claim, retry up to 3 attempts
  - workers/zeroNotesScheduler.js — 13:00 MSK generate, 07:00 MSK auto-approve,
    publish runner every 60s
  - routes/zero.js (public, no secret) — character bio + published notes for site
  - routes/zeroAdmin.js — full CRUD + manual generate button + regenerate

Settings (app_settings):
  ZERO_NOTES_CHANNEL_IDS  — csv int, channels to post for (required to enable)
  ZERO_NOTES_MODEL        — defaults to AI_MODEL_POST
  ZERO_SITE_URL_BASE      — optional, adds 'Open on site' inline button

src/routes/zero.js

@@ -0,0 +1,63 @@
+/**
+ * routes/zero.js — публичные роуты для сайта zeropost.ru/zero
+ * Монтируется на /api/zero
+ *
+ * Без аутентификации — отдаём только published.
+ */
+
+const express = require('express');
+const router  = express.Router();
+const zeroNotes = require('../services/zeroNotes');
+const zPrompt   = require('../services/zeroPrompt');
+
+// GET /api/zero/notes?limit=20&offset=0&channel_id=1
+router.get('/notes', async (req, res) => {
+  try {
+    const limit  = Math.min(parseInt(req.query.limit) || 20, 50);
+    const offset = parseInt(req.query.offset) || 0;
+    const channelId = req.query.channel_id ? parseInt(req.query.channel_id) : null;
+    const items = await zeroNotes.listPublished({ channelId, limit, offset });
+    res.json({ ok: true, items, limit, offset });
+  } catch (err) {
+    console.error('[GET /api/zero/notes]', err.message);
+    res.status(500).json({ error: err.message });
+  }
+});
+
+// GET /api/zero/notes/:id — одна published заметка
+router.get('/notes/:id', async (req, res) => {
+  try {
+    const note = await zeroNotes.getById(parseInt(req.params.id));
+    if (!note || note.status !== 'published') {
+      return res.status(404).json({ error: 'not found' });
+    }
+    // Отдаём только публичные поля
+    res.json({
+      ok: true,
+      note: {
+        id:                 note.id,
+        channel_id:         note.channel_id,
+        content:            note.content,
+        theme:              note.theme,
+        theme_bucket:       note.theme_bucket,
+        pose:               note.pose,
+        image_url:          note.image_url,
+        published_at:       note.published_at,
+        channel_message_id: note.channel_message_id,
+      },
+    });
+  } catch (err) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
+// GET /api/zero/character — bio и описание для блока "Кто такой Зеро"
+router.get('/character', async (_req, res) => {
+  res.json({
+    ok: true,
+    character: zPrompt.CHARACTER,
+    buckets: zPrompt.THEME_BUCKETS.map(b => ({ key: b.key, label: b.label })),
+  });
+});
+
+module.exports = router;