Keep SELinux mount options out of the mount destination

Appending `,z` to a mount destination (`$DATA_DIR:/data,z`) makes docker
mount a directory literally named `/data,z`. The app then writes its
database into its own container layer instead of the host volume,
`container_matches` never matches so every update recreates the container
without its data, `backup_database` silently skips, and `resolveHostPath`
refuses to provision computers (`/data/computers/1 isn't on a volume`).

Build each spec as `source:destination[:options]` instead, with the `z`
and `ro` options comma separated in the third field and the destination a
plain absolute path. `backup_database` uses the same helper.

`rescue_container_data` runs before a container whose /data is not the
host's directory is replaced: it stops the app, copies `CONTAINER:/data`
out with `docker cp`, moves a non-empty host directory aside and writes
the copy in, so repairing an install from the broken form does not lose
the database, the media or the computers' home directories.

`install.test.ts` lifts the marked `selinux-detection` and `mount-specs`
blocks out of install.sh, runs them in bash and parses the specs the way
docker does, so the two forms can't drift back.

AGENTS.md

@@ -126,6 +126,8 @@ Inspect live data with `bun llm-code-assistant/query-db.ts "<sql>"` - a read-onl
 
 `install.sh` is the only supported install and update path: `curl -fsSL https://url.moduletrace.com/cobble | sudo bash`. It is idempotent, so the same script is the updater, and `--uninstall [--purge]` is the way back out. It installs Docker when missing (Linux), creates the `cobble` network, writes `$COBBLE_HOME/install.conf` and a generated `.env` (mode 600), and starts one `cobble` container. Existing secrets are never regenerated; the database is backed up to `$COBBLE_HOME/backups` before a container is replaced. The default home is `/opt/cobble`, configurable with `--home`, and everything that must survive an update lives in its `data/` directory (`db`, `media`, `computers`, `bots`, `workspaces`, `mcp`).
 
+The bind mounts are built in the marked `selinux-detection` and `mount-specs` blocks, and `install.test.ts` runs those blocks in bash and parses the specs the way docker does. A mount spec is `source:destination[:options]`: docker takes the SELinux `z` and the read-only `ro` as comma separated options in that third field, so a destination is always a plain absolute path. Appending an option to the destination (`$DATA_DIR:/data,z`) makes docker mount a directory literally named `/data,z`: the app then writes its database to its own container layer, `container_matches` never matches, every update recreates the container without its data, `backup_database` silently skips, and `resolveHostPath` refuses to provision computers (`/data/computers/1 isn't on a volume`). `rescue_container_data` runs before a container is replaced and copies a container's unmounted `/data` onto the host, so repairing an install from the broken form does not lose its database.
+
 The app serves plain HTTP only; TLS is the reverse proxy's or tunnel's job, and the installer, the image's `HEALTHCHECK` and the dev server all assume it (`Bun.serve` gets no `tls`, there is no certificate handling anywhere). `isSecureRequest` still reads the proxy's `X-Forwarded-Proto`, so the auth and CSRF cookies get `Secure` and the installed app, Web Push and voice keep their secure context behind HTTPS; the installer binds `0.0.0.0` by default, and `--bind 127.0.0.1` limits it to a local proxy. Updates drop any `TLS_*` or `HTTP_REDIRECT_PORT` entries an older install left in `.env` and recreate a container that still mounts `/app/certs`.
 
 The container runs with `--network cobble`, `-p BIND:PORT`, `.env` at `/app/.env` read only, the host data directory at `/data`, the docker socket at `/var/run/docker.sock`, `MAIN_SERVER=1` and `PORT`, `--init`, `--cpus 1` and `--memory 2048m` (a light orchestration process: the heavy work happens in each computer's own container; overridable with `--cpus`/`--memory`), a `unless-stopped` restart policy and bounded json-file logs. `/data` must stay a bind mount: `resolveHostPath` turns paths under the app's own mounts into host paths for computer containers, and a named volume would break them. `DATA_DIR=/data` and `DB_DIR=/data/db` come from the Dockerfile; `entrypoint.sh` keeps bun-sqlite's schema record on the same volume.