Phase 9: application services and admin completion

Implements PLAN.md Phase 9. internal/appservice reads registration files
(appservice.config_files), matches namespaces the way Synapse does
(anchored at the start), and delivers events to each service as
transactions read from the roomserver's event stream at a cursor kept in
appservice_state. A transaction in flight is recorded, so after a restart
it is resent under the same ID; failures back off from 2s to 5m, and a
successful ping cuts the backoff short.

In the Client-Server API an as_token acts as the service's sender or, with
?user_id=, as any existing user in its namespace. Services register and
log in their users with m.login.application_service; exclusive user and
alias namespaces are refused to everybody else with M_EXCLUSIVE. Unknown
aliases and users in a namespace are asked of the service first. The
ping endpoint reports M_URL_NOT_SET, M_BAD_STATUS, M_CONNECTION_FAILED
and M_CONNECTION_TIMEOUT. Services' own requests, and their users' when
rate_limited is false, skip the rate limiter.

Users can change their password (POST /account/password) and deactivate
their account (POST /account/deactivate), both behind the password.
Deactivation revokes tokens, deletes devices, optionally erases the
profile and leaves every room through a new userapi.AccountObserver.

The admin API is complete: user detail, the admin flag, deactivation and
reactivation, password resets, devices, media quotas
(media.max_user_storage_bytes plus per-user overrides), registration
tokens with use limits and expiry (registration.require_token), server
notices (internal/servernotices, server_notices.*), an editor for the
federation allow/deny lists persisted in server_settings, a delivery view
of the application services, and an audit log of every change.

Migration 0011 adds the registration token, server notice room, media
quota, audit log and appservice cursor tables. Policy lists are now
returned sorted. The Complement entrypoint loads the registrations
Complement mounts in /complement/appservice.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/configuration.md

@@ -66,6 +66,7 @@ List-valued variables are comma-separated. A single `-` clears a list:
 | `federation.tls_ca_file` | `WARP_FEDERATION_TLS_CA_FILE` | empty | Extra CA certificates (PEM) for outbound federation, on top of the system roots. |
 | `media.base_path` | `WARP_MEDIA_BASE_PATH` | `./media_store` | Where media content is kept. Created on the first upload. |
 | `media.max_upload_bytes` | `WARP_MEDIA_MAX_UPLOAD_BYTES` | `52428800` | The largest upload (50 MiB), and the largest file fetched from another server. Reported to clients as `m.upload.size`. |
+| `media.max_user_storage_bytes` | `WARP_MEDIA_MAX_USER_STORAGE_BYTES` | `0` | The most one user may have uploaded in all. `0` = no limit. The admin API can give a user a quota of their own. |
 | `media.max_thumbnail_pixels` | `WARP_MEDIA_MAX_THUMBNAIL_PIXELS` | `32000000` | The largest image, in pixels, decoded to make a thumbnail. |
 | `media.thumbnail_sizes` | — | five sizes, see [media.md](media.md) | The thumbnails this server makes, as `{width, height, method}`. Empty = no thumbnails. |
 | `media.pending_upload_expiry` | `WARP_MEDIA_PENDING_UPLOAD_EXPIRY` | `24h` | How long an ID reserved with `POST /media/v1/create` waits for its content. |
@@ -77,7 +78,14 @@ List-valued variables are comma-separated. A single `-` clears a list:
 | `push.notification_retention` | `WARP_PUSH_NOTIFICATION_RETENTION` | `720h` | How long a read notification is kept for `GET /notifications`. Unread ones are kept until read. |
 | `registration.enabled` | `WARP_REGISTRATION_ENABLED` | `false` | |
 | `registration.allow_runtime_toggle` | `WARP_REGISTRATION_ALLOW_RUNTIME_TOGGLE` | `true` | |
-| `registration.tokens` | `WARP_REGISTRATION_TOKENS` | `[]` | Non-empty = sign-up also needs one of these, as the `m.login.registration_token` stage. |
+| `registration.tokens` | `WARP_REGISTRATION_TOKENS` | `[]` | Non-empty = sign-up also needs a token, as the `m.login.registration_token` stage. These never run out; tokens with a use limit or an expiry are made through the admin API, and both kinds are accepted. |
+| `registration.require_token` | `WARP_REGISTRATION_REQUIRE_TOKEN` | `false` | Ask for a token even with no `tokens` above, for a server whose tokens all come from the admin API. |
+| `appservice.config_files` | `WARP_APPSERVICE_CONFIG_FILES` | `[]` | Application service registration files, read at startup. A bad one stops the server. See [appservices.md](appservices.md). |
+| `appservice.timeout` | `WARP_APPSERVICE_TIMEOUT` | `30s` | One request to an application service: a transaction, a query or a ping. |
+| `server_notices.enabled` | `WARP_SERVER_NOTICES_ENABLED` | `false` | Create the notices user at startup and serve `POST /_warp/admin/v1/server_notices`. Needs a signing key. |
+| `server_notices.localpart` | `WARP_SERVER_NOTICES_LOCALPART` | `server-notices` | The user notices come from. Created if it does not exist, so pick a name no real user has. |
+| `server_notices.display_name` | `WARP_SERVER_NOTICES_DISPLAY_NAME` | `Server Notices` | Its display name, kept in step with this setting at startup. |
+| `server_notices.room_name` | `WARP_SERVER_NOTICES_ROOM_NAME` | `Server Notices` | The name of the room each user gets their notices in. |
 | `logging.level` | `WARP_LOG_LEVEL` | `info` | `debug`, `info`, `warn`, `error`. |
 | `logging.format` | `WARP_LOG_FORMAT` | `text` | `text` or `json`. |
 | `logging.add_source` | `WARP_LOG_ADD_SOURCE` | `false` | File and line in every record. |