merge: Phase 11.5 security remediation, invite redesign, per-node identity

Brings in the security remediation branch. Three bodies of work, and what they
changed about what this project may claim.

Phase 11.5 closed the gap between the documents and the code: the unauthenticated
node HTTP API and the TCP transport deleted, one handshake shared by the
remaining two transports, mutual authentication, structured admin transcripts,
upload confinement, group isolation, revocation that reaches nodes. Six critical
and seven high findings closed, bounded, or deferred by decision.

The invite redesign closed H3 and M3 — the last open High. The hub was the key
directory: an inviter fetched the invitee's key from it and wrapped the group key
for whatever came back, so a hub answering with its own key was handed the group
key by an honest member following the protocol exactly. That lookup is gone. The
node holds the group key and wraps it itself, for a key its recipient proves
possession of, bound to an account by a one-time code the hub never sees. M3 fell
out of the same work: node authority comes from a local roster, never from the
hub.

Per-node identity cut what remains of C4 down to one operator. A single keypair
used to be copied to every node its owner joined; each node now gets its own, so
cracking the bundle on one machine yields a key that is a stranger everywhere
else — and on that machine, one that unlocks nothing its holder did not already
serve. The bundle KDF moved to Argon2id 128 MB, and the hub stopped storing or
publishing user keys at all.

What this project may now say: the hub cannot read your content unless it ships
you malicious client code. T3 remains, accepted (D1), and is what the native
client removes. C4 is reduced, not closed, until 13.3. Chat is still plaintext at
rest until Phase 15. Draft-v5 §2 states each claim against the adversary it holds
against, which is the convention this branch exists to keep.

Four defects were found by deploying it and using a browser, none by the test
suite: a node going deaf on its hub socket, a token that predated group
membership, a client reading values before they were assigned, and identity keys
a browser held but never re-read. The lessons are recorded in CLAUDE.md.

Tests: 343 across the three packages, plus QE/deploy/e2e.py — register, pair,
invite, join, download, stream, second browser, revoke — run against the live
deployment on a wiped hub and node.

1 files changed, 38 insertions, 21 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/config.py b/packages/meshbay-node/src/meshbay_node/config.py
index a7a0785..f3752ea 100644
--- a/packages/meshbay-node/src/meshbay_node/config.py
+++ b/packages/meshbay-node/src/meshbay_node/config.py
@@ -26,28 +26,33 @@ url      = "https://meshbay.org"
 username = "myusername"
 
 [node]
-port     = 19000   # TCP+TLS (MNP v1)
-quic_port = 19010  # QUIC (MNP v2)
-http_port = 19001  # HTTP file API (public content)
-ui_port  = 18000   # local web UI
+quic_port = 19010  # QUIC (MNP) — LAN, port-forwarded, hub-less direct access
+ui_port  = 18000   # local admin UI (127.0.0.1 only)
 
-# Multiple groups — each with its own directory and ports
+# One-time codes. An invitation waits for someone to read their messages; an
+# operator pairing code is typed during the SSH session that printed it.
+invite_ttl_hours = 168   # 7 days
+pair_ttl_hours   = 24
+
+# Browser and native clients reach this node over WebRTC DataChannel via hub
+# signaling — no inbound port to open. QUIC is the optional direct path.
+
+# Multiple groups — each with its own directory
 [[groups]]
 id          = ""    # set after joining
 name        = "My Media"
 shared_dir  = "/home/user/Media"
-port        = 19000
 quic_port   = 19010
-http_port   = 19001
 
 [[groups]]
 id          = ""
 name        = "Public Archive"
 shared_dir  = "/home/user/Archive"
-port        = 19002
 quic_port   = 19012
-http_port   = 19003
-visibility  = "public"
+visibility  = "public"       # discoverable on the hub
+# join_policy = "open"       # anyone the hub says is a member gets the group key,
+                             # with no pairing code. Only for groups where that is
+                             # genuinely intended: it means the hub can join too.
 
 [keystore]
 # unlock_file = "~/.config/meshbay/unlock.key"
@@ -68,10 +73,13 @@ class HubConfig:
 
 @dataclass
 class NodeConfig:
-    port:       int = 19000
     quic_port:  int = 19010
-    http_port:  int = 19001
     ui_port:    int = 18000
+    # How long a one-time code stays usable. Invitations travel through a human
+    # conversation and are answered days later; operator pairing happens during
+    # the SSH session that printed it.
+    invite_ttl_hours: int = 168   # 7 days
+    pair_ttl_hours:   int = 24
 
 
 @dataclass
@@ -79,10 +87,16 @@ class GroupConfig:
     id:         str = ""
     name:       str = ""
     shared_dir: str = ""
-    visibility: str = "private"   # public|private
-    port:       int = 19000       # TCP+TLS MNP port for this group
+    visibility: str = "private"   # public|private — discoverability, not admission
+    # Admission. "invite" (default) means a newcomer needs a one-time pairing code
+    # before the node wraps the group key for them; "open" means the node pins
+    # whoever turns up first (TOFU) and serves them.
+    #
+    # Deliberately read from THIS file and never from the hub: a hub that could
+    # declare a group open would walk into any group it liked. Being findable
+    # (`visibility`) and being open (`join_policy`) are different questions.
+    join_policy: str = "invite"   # invite|open
     quic_port:  int = 19010       # QUIC MNP port
-    http_port:  int = 19001       # HTTP file API port
 
 
 @dataclass
@@ -121,10 +135,14 @@ def load_config(path: Path = DEFAULT_CONFIG_PATH) -> Config:
         cfg.hub.username = hub.get("username", cfg.hub.username)
 
         nd = raw.get("node", {})
-        cfg.node.port      = nd.get("port",      cfg.node.port)
+        # `port` (TCP+TLS) and `http_port` no longer exist — both listeners were removed
+        # in Phase 11.5 (findings C1, C6). Regenerate node.toml with `meshbay-node init`.
         cfg.node.quic_port = nd.get("quic_port", cfg.node.quic_port)
-        cfg.node.http_port = nd.get("http_port", cfg.node.http_port)
         cfg.node.ui_port   = nd.get("ui_port",   cfg.node.ui_port)
+        cfg.node.invite_ttl_hours = int(
+            nd.get("invite_ttl_hours", cfg.node.invite_ttl_hours))
+        cfg.node.pair_ttl_hours = int(
+            nd.get("pair_ttl_hours", cfg.node.pair_ttl_hours))
 
         # Multi-group: [[groups]] array
         if "groups" in raw:
@@ -134,9 +152,8 @@ def load_config(path: Path = DEFAULT_CONFIG_PATH) -> Config:
                     name=g.get("name", ""),
                     shared_dir=g.get("shared_dir", ""),
                     visibility=g.get("visibility", "private"),
-                    port=g.get("port", cfg.node.port),
+                    join_policy=g.get("join_policy", "invite"),
                     quic_port=g.get("quic_port", cfg.node.quic_port),
-                    http_port=g.get("http_port", cfg.node.http_port),
                 ))
         # Back-compat: single [group] section
         elif "group" in raw:
@@ -163,8 +180,8 @@ def load_config(path: Path = DEFAULT_CONFIG_PATH) -> Config:
         cfg.hub.url = url
     if user := os.environ.get("MESHBAY_USERNAME"):
         cfg.hub.username = user
-    if port := os.environ.get("MESHBAY_PORT"):
-        cfg.node.port = int(port)
+    if port := os.environ.get("MESHBAY_QUIC_PORT"):
+        cfg.node.quic_port = int(port)
 
     return cfg