v1 plan: leases, limiter, chooser, fingerprint, SQLite store, accounting, admin — acceptance tests first, no reference

Every given test compiled against a panic-only interface skeleton (go vet clean); nothing was
implemented. modernc.org/sqlite v1.59.0 vetted in a scratch module (WAL works); go.sum given.

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

docs/plans/v1/_files/example.toml

@@ -0,0 +1,26 @@
+# crossbar example configuration (v1). Replace <tailnet> and the addresses with your own.
+listen        = "127.0.0.1:17777"   # never 0.0.0.0 — bind the tailnet address in production
+db            = "crossbar.db"       # SQLite: leases + accounting (WAL). /var/lib/crossbar/crossbar.db under systemd
+poll_interval = "1s"                # 60s in production; 1s makes the smoke run quick
+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
+
+[hosts.alpha]
+base_url = "http://127.0.0.1:18081"    # e.g. http://straylight.<tailnet>:11434
+weight   = 1.0
+models   = { "ornith-1.5-35b-a3b" = { parallel = 1 }, "small-9b" = { parallel = 6 } }
+
+[hosts.beta]
+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 } }
+
+# 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.
+[routes.opencode-a]
+hosts         = ["alpha", "beta"]
+default_model = "ornith-1.5-35b-a3b"
+
+[routes.hermes-x]
+hosts = ["beta", "alpha"]