Hygiene: scripts, CI, docs and manifests

- scripts/in-namespace.sh set CARGO_TARGET_DIR to the empty string when
  it was unset, which cargo refuses, and dropped RUSTFLAGS, so the run
  in the namespace rebuilt what kernel-tests.sh had just built. Each is
  passed on only where set.
- The README's list of unsupported features still had route reflection
  and graceful restart, both of which exist; the command-line reference
  lacked SIGUSR1 and exit status 75; the HTTP API reference did not say
  what errors look like.
- The event stream said "missed 0 events" for the best-routes stream,
  which does not count what it missed; it leaves the count out now.
- CI lints bgp-bench with its count-memory feature, which nothing built.
- bgp-bench had two unused dev-dependencies; bgp-integration-tests had
  three dependencies that only its tests and examples use.
- install.sh updates apt before installing; two-routers.sh loses an
  unused variable; small things in the web crate.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

README.md

@@ -12,9 +12,9 @@ Ferrix has not been deployed in a production network.
 
 ### Unsupported Features
 
-- Route reflection, per-client best path selection for route servers, and ADD-PATH for advertised routes
+- Per-client best path selection for route servers, and ADD-PATH for advertised routes
 - TCP-AO, TCP MD5, and GTSM
-- Graceful restart, BFD, and configuration changes without a restart
+- Long-Lived Graceful Restart, BFD, and configuration changes without a restart
 - Recursive resolution of next hops that are not directly connected
 
 ### Layout
@@ -28,6 +28,8 @@ Ferrix has not been deployed in a production network.
 | `crates/fib` | The best routes in the Linux kernel, over netlink |
 | `crates/server` | Sessions, the state machine, policy, configuration |
 | `crates/web` | The status page, HTTP API and metrics |
+| `crates/integration-tests` | A test server and test peers, and the tests that run the daemon end to end |
+| `crates/bench` | Benchmarks at the scale of the Internet routing table |
 | `bin/bgp` | The daemon |
 
 ## Documentation
@@ -39,7 +41,8 @@ The documentation is a website built from [`docs/`](docs/) with
 zola --root docs serve     # http://127.0.0.1:1111
 ```
 
-- [Overview](docs/content/docs/getting-started/introduction.md) and
+- [Overview](docs/content/docs/getting-started/introduction.md),
+  [installation](docs/content/docs/getting-started/installation.md) and
   [quick start](docs/content/docs/getting-started/quick-start.md)
 - User guide: [BGP neighbors](docs/content/docs/guides/peers.md),
   [import policy](docs/content/docs/guides/import-policy.md),
@@ -47,15 +50,18 @@ zola --root docs serve     # http://127.0.0.1:1111
   [RPKI](docs/content/docs/guides/rpki.md),
   [kernel route installation](docs/content/docs/guides/kernel.md),
   [route advertisement](docs/content/docs/guides/passing-routes-on.md),
-  [configuration examples](docs/examples/)
+  [graceful restart](docs/content/docs/guides/graceful-restart.md),
+  [configuration examples](docs/content/docs/guides/examples.md)
 - [Deployment](docs/content/docs/operations/deployment.md) and
   [monitoring](docs/content/docs/operations/monitoring.md)
 - Reference: [configuration](docs/content/docs/reference/configuration.md),
+  [command line](docs/content/docs/reference/command-line.md),
   [HTTP API](docs/content/docs/reference/http-api.md),
   [metrics](docs/content/docs/reference/metrics.md),
   [supported standards](docs/content/docs/reference/rfcs.md)
-- [Architecture](docs/content/docs/development/architecture.md) and
-  [testing](docs/content/docs/development/testing.md)
+- [Architecture](docs/content/docs/development/architecture.md),
+  [testing](docs/content/docs/development/testing.md) and
+  [contributing](docs/content/docs/development/contributing.md)
 
 ## Development