feat(node): the operator can close uploading to everyone but themselves

A group where every member may add files stays the default. Some groups want a
library the operator curates, and until now the only way to get one was to
designate no upload root at all — which refuses the operator too.

**The node enforces it; the interface merely stops offering it.** The Upload
button in the Files toolbar and the paperclip in the chat composer both
disappear, which is a courtesy to the people who are not trying. The control is
`_do_file_upload` refusing with `member_upload_off`, so a member on an old tab,
or one speaking MNP directly, gets the same answer. There is a test for each,
and the enforcement test is in the node package rather than beside the UI one so
nobody reads the hidden button as the mechanism.

**Changing it is a signed operator instruction** — `OP_MEMBER_UPLOAD`, on the
same path as removing a member. An unsigned one would let any member turn it
back on and make the setting a suggestion. The transcript's subject is `on` or
`off`: what the operator is shown before signing has to name the outcome, not
the operation.

**It lives on the node**, in a new `group_settings` table in `roster.db`. Not
the hub, which has no business deciding who may write to someone else's disk.
Not `node.toml` either: that file is hand-written and full of comments recording
decisions, `ops.py` appends to it rather than round-tripping it through a
writer, and a setting toggled from a panel must not rewrite the operator's file
or need a restart. The value is cached in the group context because the upload
path is synchronous, and the signed operation updates both — storing it without
applying it would make the panel say one thing while the node did another.

**Absent means allowed**, at every layer: no row in the table, no key in the
context, no field in `handshake_ack`. An older node and an older client both
behave exactly as before, and upgrading never silently closes a group. Each of
those three has its own test, because they fail independently.

The operator is always exempt — otherwise turning it off locks them out of their
own node with a config file and a restart as the only way back. `is_node_admin`
was being computed in two places by then and is now one function, since two
copies of "is this the operator" is how the ack and the gate come to disagree.

A change reaches everyone already connected via `member_upload_ack`, so the
button goes without a reconnection. That message is both a broadcast and the
reply to the request that caused it, which is why the client does not return
early on it.

Docs updated for a cold start: draft-v6 §2.1b and change 9, a new "Where Phase
13 stands" section in CLAUDE.md recording what is built, deployed and still
missing, the module map row, and desktop-client-v1 §10b on the Settings tab and
where group settings live.

883 tests pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
index 853ae75..a0509a0 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
@@ -103,6 +103,7 @@ class MeshBayTransport {
   set onStreamEnd(fn) { this._onStreamEnd = fn; }
   set onStreamError(fn) { this._onStreamError = fn; }
   set onIndexSync(fn) { this._onIndexSync = fn; }
+  set onUploadPolicy(fn) { this._onUploadPolicy = fn; }
 
   get sessionKeys() { return this._sessionKeys; }
 
@@ -592,6 +593,24 @@ class MeshBayTransport {
    * Only the node can do this: its roster decides who it serves. Removing them
    * on the hub is the other half, and neither implies the other.
    */
+  /**
+   * Turn uploading by ordinary members on or off.
+   *
+   * Signed by the operator like any other privileged operation — the node
+   * refuses an unsigned one, which is what stops a member turning it back on.
+   */
+  async setMemberUpload(allowed, signFn) {
+    const msg = await this._sendAndWait({
+      type: 'member_upload', v: '0.1', allowed: Boolean(allowed),
+    });
+    if (msg.type === 'error') throw new Error(msg.detail);
+    if (msg.type === 'admin_challenge') {
+      return this._authorizeAdminOp(
+        msg, 'member_upload', allowed ? 'on' : 'off', signFn);
+    }
+    return msg;
+  }
+
   async revokeMember(userId, signFn) {
     const msg = await this._sendAndWait({
       type: 'member_revoke', v: '0.1', user_id: userId,
@@ -1079,6 +1098,14 @@ class MeshBayTransport {
       return;
     }
 
+    // The operator changed who may upload. Unsolicited: it arrives at everyone
+    // connected, not only at whoever asked. It still has to reach a pending
+    // caller — the operator's own request resolves on this reply — so it falls
+    // through to the matching below rather than returning here.
+    if (msg.type === 'member_upload_ack' && this._onUploadPolicy) {
+      this._onUploadPolicy(Boolean(msg.allowed));
+    }
+
     if (msg.type === 'index_sync' && msg.entries) {
       if (this._onIndexSync) this._onIndexSync(msg);
       const oldest = this._pending.entries().next();