Wire wake and identity into crossbar; v2 smoke and README

Implemented-By: OpenCode session (model recorded in docs/implementer-log.md)

example.toml

@@ -5,6 +5,7 @@ poll_interval = "1s"                # 60s in production; 1s makes the smoke run
 lease_idle    = "30m"               # a conversation idle this long loses its host
 retention     = "180d"              # per-request rows older than this are rolled up daily
 queue_max     = 1                   # waiting places per (host, model) beyond `parallel`; 503 past that
+identity      = "off"               # "tailscale" gates routes with `peers` by `tailscale whois`; "header" trusts X-Crossbar-Peer (TEST ONLY)
 
 [hosts.alpha]
 base_url = "http://127.0.0.1:18081"    # e.g. http://straylight.<tailnet>:11434
@@ -15,6 +16,10 @@ models   = { "ornith-1.5-35b-a3b" = { parallel = 1 }, "small-9b" = { parallel =
 base_url = "http://127.0.0.1:18082"    # e.g. http://titan.<tailnet>:8081
 weight   = 2.0
 models   = { "ornith-1.5-35b-a3b" = { parallel = 2 } }
+[hosts.beta.wake]                      # v2: wake a sleeping host when nothing else can take a new lease
+mac       = "aa:bb:cc:dd:ee:02"
+broadcast = "127.0.0.1:19082"          # the LAN broadcast address, port 9, in production
+wait      = "20s"
 
 # v1: a route is a set of candidate hosts; each conversation gets a sticky lease on the host with
 # the most free slots × weight at the time it starts. Pins and drains come from the admin API.
@@ -24,3 +29,4 @@ default_model = "ornith-1.5-35b-a3b"
 
 [routes.hermes-x]
 hosts = ["beta", "alpha"]
+# peers = ["talos"]                    # v2: with identity = "tailscale", only these tailnet nodes may use the route