Rebuild: coordinator (planner, NNTP pool, spool, prefetcher, leases, rule sets), node API and the edge:node worker

- groups:add / ranges:plan / nodes:create / coordinator:run commands
- the node API: lease, the range's chunks as one framed stream from the
  spool, batches, heartbeat, finish, release (node guard, token per node)
- edge:node: needs COORDINATOR_URL and NODE_TOKEN only (placeholders for
  the rest), posts a batch every 10 chunks, gives its range back on SIGTERM
- releases are gathered per batch: 1.04 chunk rows per release at 10
  chunks per batch (1.35 when built per XOVER chunk)
- partitions are checked per batch instead of remembered

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/services/planner.ts

@@ -0,0 +1,64 @@
+import db from '@adonisjs/lucid/services/db'
+import coordinatorConfig from '#config/coordinator'
+import NntpPool from '#services/nntp_pool'
+
+/**
+ * The indexed groups and their ranges (REBUILD.md, group list, coordinator).
+ * New groups get priorities after the existing ones (owner rule). A group's
+ * span from GROUP is cut into ranges of RANGE_ARTICLES; a range's priority is
+ * its position in its group's history (0 oldest … 1000 newest), so all groups
+ * start with their oldest era. Planning again only adds ranges for new articles.
+ */
+class Planner {
+  async addGroups(names: string[]): Promise<number> {
+    let added = 0
+    for (const name of names) {
+      const { rows } = await db.rawQuery(
+        `INSERT INTO groups (name, priority) SELECT ?, coalesce(max(priority), 0) + 1 FROM groups ON CONFLICT (name) DO NOTHING RETURNING id`,
+        [name]
+      )
+      added += rows.length
+    }
+    return added
+  }
+
+  /** The `top` groups matching `pattern` by article span, largest first (LIST ACTIVE). */
+  async largestGroups(pattern: string, top: number): Promise<string[]> {
+    const groups = await NntpPool.use((client) => client.listActive(pattern))
+    return groups
+      .filter((g) => g.high > g.low)
+      .sort((a, b) => b.high - b.low - (a.high - a.low))
+      .slice(0, top)
+      .map((g) => g.name)
+  }
+
+  async planGroup(group: { id: number; name: string }): Promise<number> {
+    const info = await NntpPool.use((client) => client.group(group.name))
+    const size = coordinatorConfig.rangeArticles
+    const last = await db.from('ranges').where('group_id', group.id).max('end_id as end').first()
+    const from = Math.max(info.low, Number(last?.end ?? 0) + 1)
+    const span = Math.max(1, info.high - info.low)
+    const rows = []
+    for (let start = from; start <= info.high; start += size) {
+      rows.push({
+        group_id: group.id,
+        start_id: start,
+        end_id: Math.min(start + size - 1, info.high),
+        next_id: start,
+        priority: Math.floor((1000 * (start - info.low)) / span),
+      })
+    }
+    for (let i = 0; i < rows.length; i += 2000) await db.table('ranges').multiInsert(rows.slice(i, i + 2000))
+    await db.from('groups').where('id', group.id).update({ low: info.low, high: info.high, planned_at: new Date() })
+    return rows.length
+  }
+
+  async planAll(): Promise<{ groups: number; ranges: number }> {
+    const groups = await db.from('groups').where('active', true).orderBy('priority').select('id', 'name')
+    let ranges = 0
+    for (const group of groups) ranges += await this.planGroup({ id: Number(group.id), name: group.name })
+    return { groups: groups.length, ranges }
+  }
+}
+
+export default new Planner()