Background worker that keeps the containers table in sync with
docker ps. Runs one boot pass and ticks every 30s.
Dispatch precedence per container:
1. tinyforge.workload.id label (canonical, new)
2. tinyforge.instance-id label (legacy project — joins via instances)
3. tinyforge.static-site label (legacy site)
4. com.docker.compose.project (stacks — joins via ComposeProjectName)
Rows whose Docker container ID is no longer present are flipped
to state='missing'. Placeholder rows (empty container_id, e.g.
a deploy mid-flight) are left alone so a tick that races a
deploy doesn't mark them as missing.
DockerLister interface lets tests substitute a fake daemon —
6 unit tests cover the dispatch matrix, missing-sweep, and
state normalization.
Wired into cmd/server/main.go between docker.New and the
existing startup chain. Boot pass populates the containers
table from any pre-refactor running containers.
