fix(api): mint owner peer-identity row at mesh creation

Web-first owners had no mesh.member row because the broker only ever
created one on first WS hello (CLI flow). The topic chat page server
component requires that row to issue a dashboard apikey
(issuedByMemberId is a FK to mesh.member), so visiting the chat for a
web-only mesh hit notFound() on the owner's own room.

Forward fix: createMyMesh now generates a fresh ed25519 peer keypair,
inserts a mesh.member row with role=admin and dashboardUserId=userId,
and subscribes the owner to the auto-created #general topic as 'lead'.
The peer secret key is intentionally discarded — web users don't sign
anything in v0.2.0 (no DMs, base64 plaintext on topics). If the same
user later runs the CLI, the broker mints a separate member row from
its own keypair; both work for their respective surfaces.

Backfill: apps/broker/scripts/backfill-owner-members.ts walks every
non-archived mesh whose owner has no member row, generates real
ed25519 keypairs via libsodium, inserts the rows in a transaction,
and subscribes each as 'lead' on #general. Already run against prod
— 13 owner rows minted, ddtest verified end-to-end via playwriter
(send → poll → render round-trip ok).

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

apps/broker/scripts/backfill-owner-members.ts

@@ -0,0 +1,101 @@
+/**
+ * One-shot backfill: every active mesh whose owner has no peer-identity
+ * member row gets one minted via a fresh ed25519 keypair. Without this,
+ * web-first owners (who never connected via CLI) can't access the chat
+ * surface — issueDashboardApiKey is a FK to mesh.member, and the topic
+ * page server component's owner branch picks the oldest member row in
+ * the mesh (which is null if none exist).
+ *
+ * Idempotent. Safe to re-run. Each run prints per-mesh status.
+ *
+ * Owner identification: a member is the "owner's row" when its user_id
+ * matches mesh.owner_user_id. The script targets meshes that have zero
+ * such matching rows (regardless of total member count — a mesh with
+ * peers but no owner member also gets a fresh owner row).
+ *
+ * The owner row is also auto-subscribed to #general as 'lead' so the
+ * unread/role accounting matches CLI-flow meshes.
+ *
+ * Usage:
+ *   DATABASE_URL=... bun apps/broker/scripts/backfill-owner-members.ts
+ */
+
+import postgres from "postgres";
+import sodium from "libsodium-wrappers";
+
+interface Orphan {
+  meshId: string;
+  slug: string;
+  ownerUserId: string;
+  meshName: string;
+}
+
+async function main() {
+  const url = process.env.DATABASE_URL;
+  if (!url) {
+    console.error("DATABASE_URL not set");
+    process.exit(2);
+  }
+
+  await sodium.ready;
+
+  const sql = postgres(url, { max: 1, onnotice: () => {} });
+  try {
+    const orphans = await sql<Orphan[]>`
+      SELECT m.id AS "meshId", m.slug, m.owner_user_id AS "ownerUserId", m.name AS "meshName"
+      FROM mesh.mesh m
+      WHERE m.archived_at IS NULL
+        AND NOT EXISTS (
+          SELECT 1 FROM mesh.member mm
+          WHERE mm.mesh_id = m.id
+            AND mm.revoked_at IS NULL
+            AND mm.user_id = m.owner_user_id
+        )
+      ORDER BY m.created_at
+    `;
+    console.log(`backfill · ${orphans.length} meshes need an owner member row`);
+
+    let inserted = 0;
+    for (const o of orphans) {
+      const kp = sodium.crypto_sign_keypair();
+      const peerPubkey = sodium.to_hex(kp.publicKey);
+      const id = sodium.to_hex(sodium.randombytes_buf(16));
+      try {
+        await sql.begin(async (tx) => {
+          await tx`
+            INSERT INTO mesh.member (
+              id, mesh_id, peer_pubkey, display_name, role,
+              user_id, dashboard_user_id
+            )
+            VALUES (
+              ${id}, ${o.meshId}, ${peerPubkey},
+              ${o.meshName + "-owner"}, ${"admin"}::mesh.role,
+              ${o.ownerUserId}, ${o.ownerUserId}
+            )
+          `;
+          // Subscribe to #general as 'lead' if the topic exists.
+          await tx`
+            INSERT INTO mesh.topic_member (topic_id, member_id, role)
+            SELECT t.id, ${id}, ${"lead"}::mesh.topic_member_role
+            FROM mesh.topic t
+            WHERE t.mesh_id = ${o.meshId} AND t.name = 'general'
+            ON CONFLICT (topic_id, member_id) DO NOTHING
+          `;
+        });
+        inserted += 1;
+        console.log(`  + ${o.slug.padEnd(20)} owner=${o.ownerUserId.slice(0, 8)}… member=${id.slice(0, 8)}… pk=${peerPubkey.slice(0, 12)}…`);
+      } catch (e) {
+        console.error(`  ✗ ${o.slug}: ${(e as Error).message}`);
+        throw e;
+      }
+    }
+    console.log(`backfill done · ${inserted} owner member rows inserted`);
+  } finally {
+    await sql.end({ timeout: 5 });
+  }
+}
+
+main().catch((e) => {
+  console.error("backfill failed:", e);
+  process.exit(1);
+});