automc: schema-fit query + CI + FORK doc

- pgsync.go: filter rows where enabled IS NOT FALSE and domain IS NOT NULL,
  matching the existing automc servers table (domain nullable, enabled
  defaults true). Trigger doc now includes UPDATE OF enabled.
- .gitea/workflows/ci.yaml: build/test on push to automc branch + tags,
  publish container as git.timemachine.center/timemachine/mc-router:automc.
- FORK.md: soft-fork relationship doc at repo root.
- docs/AUTOMC.md: quick-start recipe, troubleshooting table,
  sync-lifecycle and waker-dispatch sequence diagrams.

FORK.md

@@ -0,0 +1,51 @@
+# Fork status — Timemachine/mc-router
+
+This is a **soft fork** of [`itzg/mc-router`](https://github.com/itzg/mc-router) maintained for the [automc](https://git.timemachine.center/Timemachine/automc) Minecraft management platform.
+
+## Branch model
+
+| Branch | Tracks | Contents |
+|---|---|---|
+| `main` | `upstream/main` (github.com/itzg/mc-router) | Verbatim mirror. **Do not commit here.** |
+| `automc` | branched from `v1.42.1` | Soft fork; carries the automc-specific patch. |
+
+## Patch surface
+
+Minimal — designed for low-friction rebases.
+
+| Path | Type | Why |
+|---|---|---|
+| `cmd/mc-router/main.go` | edit | 1 import line + 4-line `automc.Wire(ctx)` call. Only upstream file modified. |
+| `internal/automc/` | new dir | Self-contained extension package — no upstream conflicts possible. |
+| `docs/AUTOMC.md` | new | Operator doc for the extensions. See [`docs/AUTOMC.md`](docs/AUTOMC.md). |
+| `Makefile` | edit | Appended `sync-upstream` + `automc-build` targets. |
+| `go.mod` / `go.sum` | edit | Added `github.com/jackc/pgx/v5 v5.8.0` for LISTEN/NOTIFY. |
+| `FORK.md` | new | This file. |
+
+Everything else stays untouched. No edits to `server/`, `mcproto/`, `cmd/mc-router/` beyond the wire-call.
+
+## What the fork adds
+
+1. **Postgres LISTEN/NOTIFY route source** — drop-in alternative to `--routes-config`, `--api-binding`, K8s, and Docker route sources. Pulled in via `AUTOMC_DSN` env var.
+2. **HTTP waker integration** — registers a `WakerFunc` per route that POSTs to a control-plane (`AUTOMC_WAKER_URL`) and polls until `state=running`.
+
+Both are opt-in. With `AUTOMC_DSN` unset, the binary behaves exactly like upstream `itzg/mc-router`.
+
+See [`docs/AUTOMC.md`](docs/AUTOMC.md) for env vars, schema, troubleshooting.
+
+## Sync from upstream
+
+```
+make sync-upstream
+```
+
+Rebases `automc` onto `upstream/main`, runs `go build ./...` and `go test ./internal/automc/...`. If `server.Routes.CreateMapping` signature changes, only [`internal/automc/pgsync.go`](internal/automc/pgsync.go) needs adjustment.
+
+## Reporting issues
+
+| Where it goes | What |
+|---|---|
+| [`Timemachine/mc-router`](https://git.timemachine.center/Timemachine/mc-router/issues) | automc-specific bugs (pg sync, waker, fork mechanics) |
+| [`itzg/mc-router`](https://github.com/itzg/mc-router/issues) | Upstream core bugs (routing, mcproto, REST API) |
+
+If unsure, file upstream first — most reports turn out to be upstream-side.