fix(api): /v1/me/peer-pubkey only updates web-managed members

Adds a 409 not_web_member guard to POST /v1/me/peer-pubkey: the
endpoint will only rewrite peer_pubkey on members that have
dashboard_user_id set. CLI members own their on-disk keypair —
overwriting their stored peer_pubkey would break the next WS hello
because the signature verification would fail against the new
pubkey.

In practice this restriction is invisible to the legitimate browser
flow: the dashboard always mints its apikey against the web member
(dashboard_user_id is non-null by construction in mutations.ts).
Guard ensures a misuse (e.g. a CLI-minted apikey being used to call
peer-pubkey) gets a clear 409 instead of silently breaking the CLI's
auth.

Discovered during phase 3.5 smoke when a CLI-minted apikey clobbered
the only openclaw member (CLI-owned) and the user's CLI signature
would have stopped verifying on the next launch.

packages/api/src/modules/mesh/v1-router.ts

@@ -305,12 +305,33 @@ export const v1Router = new Hono<Env>()
       const body = c.req.valid("json");
       const newPubkey = body.pubkey.toLowerCase();
       const [existing] = await db
-        .select({ peerPubkey: meshMember.peerPubkey })
+        .select({
+          peerPubkey: meshMember.peerPubkey,
+          dashboardUserId: meshMember.dashboardUserId,
+        })
         .from(meshMember)
         .where(eq(meshMember.id, key.issuedByMemberId));
       if (!existing) {
         return c.json({ error: "member_not_found" }, 404);
       }
+      // Safety: only web-managed members (dashboardUserId set) can have
+      // their peer_pubkey rewritten via this endpoint. CLI-created
+      // members hold a real on-disk secret that matches their existing
+      // peer_pubkey; overwriting it would break their next WS hello
+      // (signature verification fails because the stored pubkey no
+      // longer matches the secret they sign with). The browser flow
+      // always mints its apikey against the dashboard member, so this
+      // restriction is invisible to legitimate callers.
+      if (!existing.dashboardUserId) {
+        return c.json(
+          {
+            error: "not_web_member",
+            detail:
+              "this endpoint only updates web-managed members (mesh.member.dashboard_user_id IS NOT NULL); CLI members own their on-disk keypair and can't have peer_pubkey rewritten remotely",
+          },
+          409,
+        );
+      }
       const changed = existing.peerPubkey !== newPubkey;
       if (changed) {
         await db