Retire the tcp-chain static test topology

The tcp-chain profile has never been runnable. ping-test.sh dispatches on
chain and mesh only, and the string tcp-chain has never appeared in that
script in its history, so invoking the profile has always fallen through
to the unknown-profile branch: silently asserting nothing before that
branch was made to fail, and exiting 2 since. Neither runner referenced
it either.

What it would have covered is already covered. The chaos tcp-mesh
scenario runs in local CI and gives TCP a discriminating gate: n04's only
edges are TCP, so if the transport were broken n04 could not parent and
the scenario's baseline assertion would fail. It also carries a pure-TCP
two-hop path, n01 to n04 to n05, under netem and link flaps. The only
residual tcp-chain would have added is a mesh with no UDP present
anywhere, which is not worth a fixture that has never run.

Remove the topology, its three compose services, and the documentation
rows. Every profile the static compose file still defines is now
exercised by a suite.

Also correct the chaos README, which has listed tcp-only and tcp-chain in
its transport table since those two scenarios were deleted in 9e63b42.
Neither has existed for months.

testing/README.md

@@ -16,7 +16,6 @@ configurations.
 | ----------- | ----- | --------- | -------------------------------- |
 | mesh        | 5     | UDP       | Sparse mesh, 6 links, multi-hop  |
 | chain       | 5     | UDP       | Linear chain, max 4-hop paths    |
-| tcp-chain   | 3     | TCP       | Linear chain over TCP (port 8443) |
 | rekey       | 5     | UDP       | Rekey integration test topology  |
 
 ### [tor/](tor/) -- Tor Transport Integration

testing/chaos/README.md

@@ -67,19 +67,12 @@ Explicit topologies exercising non-UDP transports.
 | ------------- | ----- | -------------- | ----- | -------- | ----- | ---------- | ------------------------------------------ |
 | ethernet-only | 4     | Ethernet       | Ring  | 90s      | yes   | --         | AF_PACKET transport with beacon discovery  |
 | ethernet-mesh | 6     | UDP + Ethernet | Mesh  | 120s     | yes   | yes        | Mixed UDP/Ethernet, netem mutation + flaps |
-| tcp-only      | 4     | TCP            | Ring  | 90s      | yes   | --         | TCP transport with static peer config      |
-| tcp-chain     | 4     | TCP            | Chain | 90s      | yes   | --         | TCP multi-hop routing through chain        |
 | tcp-mesh      | 6     | UDP + TCP      | Mesh  | 120s     | yes   | yes        | Mixed UDP/TCP, netem mutation + flaps      |
 
 - **ethernet-only**: 4-node ring on raw Ethernet (AF_PACKET). Peers discovered
   via beacons, not static config. Minimal netem (1-5ms delay).
 - **ethernet-mesh**: Mirrors `tcp-mesh` topology but with Ethernet instead of
   TCP. UDP edges use static config; Ethernet edges use beacon discovery.
-- **tcp-only**: 4-node ring using TCP on port 8443. Tests connect-on-send,
-  FMP framing over TCP, and reconnection. Netem enabled (1-10ms delay, 0-1%
-  loss).
-- **tcp-chain**: 4-node linear chain, all TCP. Tests multi-hop routing over
-  TCP-only mesh.
 - **tcp-mesh**: 6-node mesh with 4 UDP and 3 TCP edges. Both transports use
   static peer config. Netem mutation (30% fraction, every 20-40s) and link
   flaps (1 link max, 10-20s down).

testing/static/README.md

@@ -119,16 +119,13 @@ testing/static/
 │   └── topologies/
 │       ├── mesh.yaml                   # Mesh topology definition
 │       ├── chain.yaml                  # Chain topology definition
-│       ├── tcp-chain.yaml             # TCP chain (3 nodes, port 8443)
 │       └── rekey.yaml                 # Rekey integration test (5 nodes)
 ├── generated-configs/                  # Auto-generated, run-scoped (gitignored)
 │   ├── npubs.env                       # NPUB_A=..., NPUB_B=..., etc.
 │   ├── mesh/
 │   │   ├── node-a.yaml ... node-e.yaml
-│   ├── chain/
+│   └── chain/
-│   │   ├── node-a.yaml ... node-e.yaml
+│       ├── node-a.yaml ... node-e.yaml
-│   └── tcp-chain/
-│       ├── node-a.yaml ... node-c.yaml
 ├── scripts/
 │   ├── build.sh                        # Build binary + generate configs
 │   ├── generate-configs.sh             # Generate node configs from topology

testing/static/configs/topologies/tcp-chain.yaml

@@ -1,29 +0,0 @@
-# TCP Chain Topology Definition
-#
-# Three nodes with TCP links forming a linear chain. Tests basic TCP
-# transport connectivity, spanning tree convergence, and multi-hop
-# routing over TCP. All peer connections use TCP on port 443.
-#
-# default_transport: tcp tells the config generator to use TCP
-# transport and port 443 instead of the default UDP/2121.
-
-default_transport: tcp
-
-nodes:
-  a:
-    nsec: "0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20"
-    npub: "npub1sjlh2c3x9w7kjsqg2ay080n2lff2uvt325vpan33ke34rn8l5jcqawh57m"
-    docker_ip: "172.20.0.10"
-    peers: [b]
-
-  b:
-    nsec: "b102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1fb0"
-    npub: "npub1tdwa4vjrjl33pcjdpf2t4p027nl86xrx24g4d3avg4vwvayr3g8qhd84le"
-    docker_ip: "172.20.0.11"
-    peers: [a, c]
-
-  c:
-    nsec: "c102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1fc0"
-    npub: "npub1cld9yay0u24davpu6c35l4vldrhzvaq66pcqtg9a0j2cnjrn9rtsxx2pe6"
-    docker_ip: "172.20.0.12"
-    peers: [b]

testing/static/docker-compose.yml

@@ -365,40 +365,6 @@ services:
     networks:
       fips-net:
 
-  # ── TCP chain topology (A-B-C) ───────────────────────────────
-  tcp-a:
-    <<: *fips-common
-    profiles: ["tcp-chain"]
-    container_name: fips-node-a${FIPS_CI_NAME_SUFFIX:-}
-    hostname: node-a
-    volumes:
-      - ../docker/resolv.conf:/etc/resolv.conf:ro
-      - ./generated-configs${FIPS_CI_NAME_SUFFIX:-}/tcp-chain/node-a.yaml:/etc/fips/fips.yaml:ro
-    networks:
-      fips-net:
-
-  tcp-b:
-    <<: *fips-common
-    profiles: ["tcp-chain"]
-    container_name: fips-node-b${FIPS_CI_NAME_SUFFIX:-}
-    hostname: node-b
-    volumes:
-      - ../docker/resolv.conf:/etc/resolv.conf:ro
-      - ./generated-configs${FIPS_CI_NAME_SUFFIX:-}/tcp-chain/node-b.yaml:/etc/fips/fips.yaml:ro
-    networks:
-      fips-net:
-
-  tcp-c:
-    <<: *fips-common
-    profiles: ["tcp-chain"]
-    container_name: fips-node-c${FIPS_CI_NAME_SUFFIX:-}
-    hostname: node-c
-    volumes:
-      - ../docker/resolv.conf:/etc/resolv.conf:ro
-      - ./generated-configs${FIPS_CI_NAME_SUFFIX:-}/tcp-chain/node-c.yaml:/etc/fips/fips.yaml:ro
-    networks:
-      fips-net:
-
   # ── Gateway integration test (gateway + server + non-FIPS client) ─
   gw-gateway:
     <<: *fips-common