Phase 1: accounts and sessions

Implements PLAN.md Phase 1. A client can now register, log in, manage its
devices and set its profile; an operator can create accounts and flip the
runtime switches. There are still no rooms and no real /sync.

userapi: accounts, argon2id passwords in PHC format, devices, access and
refresh tokens stored as SHA-256 hashes, account data and the admin flag.
Its storage interface is storage.UserStore, implemented once in sqlstore
with `?` placeholders; the postgres driver supplies a rebind function and
unique-violation recognition rather than keeping a second copy of thirty
statements. Timestamps in these tables are int64 milliseconds, the unit the
Client-Server API uses on the wire.

Client-Server API: register (user-interactive auth with m.login.dummy and
optional registration tokens), register/available, token validity, login
with m.login.password, logout, logout/all, refresh, account/whoami,
capabilities, devices/* with password-gated deletion, profile/*, global and
per-room account data.

GET /sync is a deliberate placeholder: it answers a valid token with an
empty but well-formed response and refuses a revoked one. Phase 1 has no
rooms, so that is the whole truth, and it is what makes session revocation
observable. Phase 4 replaces it with the syncapi.

Auth middleware resolves a bearer token (header or the legacy query
parameter) to a device and user, answering an expired token with the soft
logout the spec asks for. Rate limiting is a token bucket per endpoint class
keyed on the client address, returning M_LIMIT_EXCEEDED with retry_after_ms.

adminapi v1 under /_warp/admin/v1: admin-only auth via a normal Matrix
token, GET/PUT /federation and /registration driving internal/settings and
reporting a config-pinned switch as a 409, GET/POST /users, GET /stats.

warp create-account [--admin] creates the first account straight in the
database, so a new install with registration off has a way in.

Complement is wired up for the federation=off profile: an image meeting its
contract, an entrypoint that configures Warp entirely from WARP_*
variables, and a runner that builds, clones and executes the target set
(TestRegistration, TestLogin, TestDeviceManagement). It has not been run
yet -- there is no container runtime on the development machine -- so the
three tests' assertions were read from the Complement sources and pinned as
httptest tests instead, and CI gained a job that runs the real thing.

Also fixes a .gitignore bug from Phase 0: the unanchored `warp` pattern,
meant for the built binary, also matched the directory server/cmd/warp and
silently excluded the entire command package from the repository. The
binary patterns are now anchored to the repository root, and cmd/warp is
committed for the first time.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

server/test/complement/entrypoint.sh

@@ -0,0 +1,50 @@
+#!/bin/sh
+# Start Warp the way Complement needs it.
+#
+# There is no configuration file: every setting Warp has can come from a
+# WARP_* environment variable, so the whole deployment is the few lines
+# below. Complement may run this entrypoint more than once against the same
+# container, so everything here is idempotent.
+set -eu
+
+DATA_DIR="${WARP_DATA_DIR:-/data}"
+mkdir -p "$DATA_DIR"
+
+# Complement names the homeservers hs1, hs2, ... and passes the name in.
+export WARP_SERVER_NAME="${SERVER_NAME:-hs1}"
+
+export WARP_PRIVATE_KEY="$DATA_DIR/signing.key"
+export WARP_DB_DRIVER=sqlite
+export WARP_DB_CONNECTION_STRING="file:$DATA_DIR/warp.db?_pragma=journal_mode(WAL)&_pragma=busy_timeout(10000)&_pragma=foreign_keys(1)"
+export WARP_DB_AUTO_MIGRATE=true
+
+export WARP_LISTEN_ADDRESS=":8008"
+
+# The suite registers and logs in constantly, all from the one address the
+# test runner has. Rate limiting would turn that into a wall of
+# M_LIMIT_EXCEEDED and tell us nothing about the server. Synapse's own
+# Complement image does the same.
+export WARP_RATE_LIMIT_ENABLED=false
+
+# Open registration: the tests create their own users.
+export WARP_REGISTRATION_ENABLED=true
+
+# Federation stays off unless the profile asks for it. Phase 5 adds the
+# TLS listener on 8448 that the federation profile needs; until then this
+# image only serves the Client-Server API.
+export WARP_FEDERATION_ENABLED="${WARP_FEDERATION_ENABLED:-false}"
+
+# Complement captures the container's output, so text at debug level is the
+# most useful thing to have when a test fails.
+export WARP_LOG_LEVEL="${WARP_LOG_LEVEL:-debug}"
+export WARP_LOG_FORMAT="${WARP_LOG_FORMAT:-text}"
+
+if [ ! -f "$WARP_PRIVATE_KEY" ]; then
+	warp generate-keys --output "$WARP_PRIVATE_KEY"
+fi
+
+# Migrations also run on boot, but doing them here keeps a schema failure
+# out of the request path and makes it obvious in the container log.
+warp migrate
+
+exec warp serve