kvitt/infra/README.md

# infra: Kvitt infrastructure

This file covers the **development stack on the owner's Mac** (`infra/dev/`, milestone M2c-dev, D-001), the
**Firebase setup** (SPEC §10.7) and the **Pi stack** (`infra/pi/`, milestone M2c-pi, D-100): a self-contained
bundle the owner copies to the Kvitt Pi and runs there. No agent and no Mac script connects to the Pis; the owner
runs every Pi command from the checklist in "Pi: what the owner does".

## Layout

| Path | What |
|---|---|
| `dev/compose.yaml` | Dev stack: `server` (image `kvitt-server:dev`) and the on-demand `backup` job |
| `dev/.env.example` | Dev settings, no secret values; copy to `dev/.env` (git-ignored) to override |
| `dev/build.sh` | Builds `kvitt-server:dev` from `server/Dockerfile` and `kvitt-backup:dev` from `backup/Dockerfile` |
| `dev/up.sh` | Starts the server, waits for `/health`, prints the Mac and phone URLs; `--down` stops the stack |
| `dev/logs.sh` | Follows the logs (`dev/logs.sh --tail 100 server`) |
| `dev/backup.sh` | Runs the backup job once and checks the snapshot with `PRAGMA integrity_check` |
| `dev/copy-google-services.sh` | Copies `secrets/google-services.json` to `android/app/google-services.json` |
| `dev/lib.sh` | Helpers sourced by the scripts |
| `backup/Dockerfile`, `backup/backup.sh`, `backup/healthcheck.sh` | Backup image and job of SPEC §10.9 (shared with the Pi stack); Drive upload and D-002 deletion |
| `cert-sync/Dockerfile`, `cert-sync/sync.sh`, `cert-sync/entrypoint.sh` | Certificate sync image of SPEC §10.5.1 |
| `pi/` | **The Pi bundle** (copied to the Kvitt Pi): `compose.yaml`, `Caddyfile`, `.env.example`, `install.sh`, `deploy.sh`, `bootstrap.sh`, `backup-now.sh`, `install-apk.sh`, `lib.sh`; git-ignored `pi/.env`, `pi/secrets/`, `pi/out/` |
| `build-images.sh` | Mac fallback for the image build: linux/arm64, push to the Gitea registry |
| `publish-apk.sh` | Mac: release APK, mapping and `latest.json` into `pi/out/apk/` for the owner to copy to the Pi |
| `RESTORE.md` | Restore from a Drive backup, step by step (SPEC §10.9) |
| `../.gitea/workflows/build-images.yaml` | Gitea Actions image build (the normal path) |
| `secrets/` | Git-ignored: `fcm-service-account.json`, `google-services.json`, `ha_ssh_key(.pub)`, `rclone.conf`, optional `registry.env`. Never committed |

All Mac commands below run from the repository root of the main checkout (`/Users/jhag/projects/kvitt`).

## Development stack

**Choices.** No Caddy and no TLS: debug builds accept `http://` to private LAN addresses (AC-2.8), so the server
publishes its own port (default 8080) on all of the Mac's interfaces. The server keeps the hardening of SPEC §8.9
(uid 10001, read-only root, no capabilities, `no-new-privileges`), the 160 MiB limit, `json-file` logging
(10 MB x 3) and `TZ=Europe/Stockholm`. Data lives in the bind-mounted folder `infra/dev/data/` (git-ignored) so it
is easy to inspect and reset. The secrets folder is mounted read-only at `/secrets`; if
`fcm-service-account.json` is missing the server runs with push disabled (§10.4).

On this Mac `docker` is Podman (`docker compose` runs `podman-compose`); the files work with Docker Desktop as well.

### Build

```bash
infra/dev/build.sh            # both images
infra/dev/build.sh server     # only kvitt-server:dev; needs server/Dockerfile (milestone M2a)
infra/dev/build.sh backup     # only kvitt-backup:dev
```

The server build is `docker build --platform linux/arm64 -f server/Dockerfile -t kvitt-server:dev server`
(override the context with `KVITT_SERVER_BUILD_CONTEXT`). The script refuses to run while a Gradle build holds
`/tmp/kvitt-gradle.lock` (CLAUDE.md).

### Start, stop, logs

```bash
infra/dev/up.sh               # start; prints health, the Mac URL and the phone URL
infra/dev/logs.sh             # follow logs (Ctrl-C to stop following)
infra/dev/up.sh --down        # stop and remove the containers (data stays in infra/dev/data/)
```

`KVITT_PUBLIC_URL` (used in invite links) is left empty in `.env.example`; `up.sh` sets it to
`http://<Mac LAN address>:<port>`. Pin it in `infra/dev/.env` if the Mac's address changes often.

### Finding the Mac's LAN address

`up.sh` prints it. By hand: `ipconfig getifaddr en0` (Wi-Fi on most Macs), or the interface of the default route:
`route -n get default | grep interface`, then `ipconfig getifaddr <interface>`. It must be a private address
(`192.168.*`, `10.*`, `172.16.*` to `172.31.*`) for a debug build to accept `http://` (AC-2.8).

The first time a phone connects, macOS may ask whether the container runtime (Podman's `gvproxy`, or Docker)
may accept incoming network connections: answer Allow.

### Bootstrap and pairing a debug build

The `bootstrap` and `pair-device` subcommands (SPEC §10.4, AC-1.1, AC-1.6) arrive with the server milestones.

```bash
C="docker compose -f infra/dev/compose.yaml --env-file infra/dev/.env.example"   # or --env-file infra/dev/.env
$C exec server kvitt-server bootstrap                      # first admin invite: code, link, expiry
$C exec server kvitt-server pair-device --user <user_id>   # extra device invite for an existing user
$C exec server kvitt-server invite-partner                 # partner invite by the admin, as E-12 (D-113)
$C run --rm server migrate                                 # when the server is stopped (entrypoint is kvitt-server)
```

On the phone (home Wi-Fi, debug build `se.hagstedt.kvitt.debug`): open the pairing screen, enter the server URL
`http://<Mac LAN address>:8080` and the printed code (AC-2.7). Check reachability first by opening
`http://<Mac LAN address>:8080/health` in Chrome on the phone: it shows `"status":"ok"`.

### Backup (local, no Drive upload)

```bash
infra/dev/backup.sh
```

Runs `infra/backup/backup.sh` once in the `backup` image (compose profile `backup`, so `up` never starts it) with
`RCLONE_FOLDER_ID` empty: `.backup` snapshot, `PRAGMA integrity_check` must print `ok`, then
`infra/dev/backups/kvitt-<UTC stamp>.sqlite.gz`, `pictures-<stamp>.tar.gz` and `last-success`; the Drive upload
is skipped with a log line and the files are kept (SPEC §10.9, D-001). The wrapper then checks the new snapshot
again. To check by hand: `gunzip -c infra/dev/backups/kvitt-<stamp>.sqlite.gz > /tmp/k.sqlite && sqlite3 /tmp/k.sqlite "PRAGMA integrity_check"`.

### Resetting the dev data

```bash
infra/dev/up.sh --down
rm -rf infra/dev/data         # the dev database, pictures and APKs; never the phones' data
infra/dev/up.sh               # fresh database; run bootstrap again
```

Paired debug builds then hold a token the new database does not know: re-pair them (clear the debug app's data on
the phone, or reinstall the debug build).

### Worktrees

Agents work in `.claude/worktrees/agent-<id>`, which has no `infra/secrets/` unless copied (CLAUDE.md). Either copy
it from the main checkout, or set `KVITT_SECRETS_DIR=/Users/jhag/projects/kvitt/infra/secrets` in `infra/dev/.env`.
`infra/dev/copy-google-services.sh /Users/jhag/projects/kvitt` copies the Firebase config from the main checkout
into the worktree's `android/app/`.

## Firebase (SPEC §10.7)

Project `kvitt-1337` (Firebase added to the existing Google Cloud project). Free tier only; nothing billable is
created by this setup.

| Resource | Name |
|---|---|
| APIs enabled | `firebase.googleapis.com`, `fcm.googleapis.com`, `cloudresourcemanager.googleapis.com`, `iam.googleapis.com` |
| Android app | "Kvitt", package `se.hagstedt.kvitt` |
| Android app | "Kvitt debug", package `se.hagstedt.kvitt.debug` |
| Service account | `kvitt-fcm@kvitt-1337.iam.gserviceaccount.com` ("Kvitt FCM sender"), role `roles/firebasecloudmessaging.admin` (the narrowest predefined role holding `cloudmessaging.messages.create`) |
| Key | `infra/secrets/fcm-service-account.json` (git-ignored, mode 600) |
| Config | `infra/secrets/google-services.json`, one file with both Android clients (git-ignored) |

Put the config where Gradle reads it: `infra/dev/copy-google-services.sh`.

The setup used only `gcloud` and the Firebase Management REST API. To repeat or inspect it:

```bash
T=$(gcloud auth print-access-token)
H=(-H "Authorization: Bearer $T" -H "x-goog-user-project: kvitt-1337")
API=https://firebase.googleapis.com/v1beta1/projects/kvitt-1337
curl -sS "${H[@]}" "$API/androidApps"                                 # list the apps (ids, packages)
curl -sS "${H[@]}" "$API/androidApps/<appId>/config"                   # configFileContents is base64 google-services.json
gcloud iam service-accounts keys list --iam-account kvitt-fcm@kvitt-1337.iam.gserviceaccount.com --project kvitt-1337
```

Rotating the key: create a new one with
`gcloud iam service-accounts keys create infra/secrets/fcm-service-account.json --iam-account kvitt-fcm@kvitt-1337.iam.gserviceaccount.com --project kvitt-1337`,
restart the server, then delete the old key id with `gcloud iam service-accounts keys delete <key id> ...`.
Copying the key to the Pi (§10.7 step 7, mode 0440, group 10001) is done by `pi/install.sh` ("Pi: what the owner does", step 6).

## Pi stack (SPEC §10.1 to §10.10, D-100)

### How it fits together

| Where | What runs | Who runs it |
|---|---|---|
| Gitea Actions (runner label `host`, a Raspberry Pi) | `.gitea/workflows/build-images.yaml`: builds `kvitt-server`, `kvitt-cert-sync`, `kvitt-backup` for linux/arm64, pushes them to `gitea.lan/jacobh2/...` tagged `vMAJOR.MINOR.PATCH` and `latest`, pushes the git tag | Gitea, on a push to `server/**`, `infra/cert-sync/**`, `infra/backup/**`, `.gitea/workflows/**`, or by hand (Actions, "Run workflow") |
| Owner's Mac | `infra/build-images.sh [tag]` (fallback image build), `infra/publish-apk.sh` (release APK into `infra/pi/out/apk/`) | The owner (or an agent, for the APK build only) |
| Kvitt Pi, `/opt/kvitt/` | `compose.yaml`, `Caddyfile`, `.env`, `secrets/`, `import/`, `apk/`, and the scripts `deploy.sh`, `bootstrap.sh`, `backup-now.sh`, `install-apk.sh` (copied there by `install.sh`) | The owner, in their own SSH session |
| Home Assistant Pi | Its own certbot renews `icehack.asuscomm.com`; cert-sync reads the two PEM files over SSH with a dedicated key | Untouched apart from one `authorized_keys` entry |

Stack (`pi/compose.yaml`, project name `kvitt`): `caddy` (publishes 8443, the only published port), `server`,
`cert-sync`, `backup`; volumes `data`, `certs`, `caddy_data`, `backups`; network `kvitt`; every service
`restart: unless-stopped`, json-file logs 10 MB x 3, `TZ=Europe/Stockholm`. Images are
`${KVITT_REGISTRY}/kvitt-server|kvitt-cert-sync|kvitt-backup:${KVITT_TAG}` with `KVITT_REGISTRY=gitea.lan/jacobh2`
(D-104; the names the workflow pushes).

### Versions (resolved 2026-10-18)

| Component | Version | Source |
|---|---|---|
| Caddy | `caddy:2.11.7@sha256:685ae3d7c34d9b5f8caeddc5d14051db7bbd88ff1f5a2fa0c16bd8ca328fb7af` (multi-arch index; has linux/arm64/v8) | Docker Hub official image; tag `2.11.7` = `2.11` = `latest`, pushed 2026-10-14 |
| Alpine (cert-sync, backup) | `alpine:3.24.2@sha256:294b683cb724975bec92580e1e685676bd4b50bda910ddb8c51d4cabeaec77e6` | Docker Hub official image; `3.24` = `latest` |
| cert-sync packages (Alpine v3.24) | openssh-client-default 10.3_p1-r1, curl 8.22.0-r0, openssl 3.5.9-r0, supercronic 0.2.49-r1, tzdata 2026e-r0 | `apk policy` in the pinned image |
| backup packages (Alpine v3.24) | sqlite 3.53.4, rclone 1.74.1, tar 1.35, tzdata 2026e (M2c-dev), supercronic 0.2.49-r1 | `apk policy` in the pinned image |
| Docker Engine on the Pi | Docker's Debian apt repository, arm64 packages (`docker-ce` 5:29.8.2 current): `docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin` | docs.docker.com/engine/install/raspberry-pi-os/: that page is for 32-bit (armhf) only; 64-bit Raspberry Pi OS uses the Debian instructions (docs.docker.com/engine/install/debian/) |

**Why supercronic, not busybox crond (D-104).** Both sidecars run as non-root users (cert-sync uid 1000, backup
uid 10001). Busybox crond started as a non-root user in alpine 3.24.2 never ran a job (tested 2026-10-18: an
every-minute job produced no output in two minutes). supercronic is a cron for containers that runs jobs as the
user it runs as and honours `TZ`; the schedules are unchanged (`0 4 * * *` cert-sync, `30 3 * * *` backup).

### Backup uid (D-105, SPEC §10.2 "M2c-pi reconciles the two")

`backup` runs as **uid 10001**, the server's uid, on the Pi as on the Mac: `sqlite3 .backup` on a WAL database
must open (and write) `kvitt.sqlite-shm`, which the server creates as 10001 with mode 0644, so uid 1000 could not
back up the live database without loosening the server's files. Therefore `/opt/kvitt/secrets/rclone.conf` is
mode 0600 **owned by 10001:10001** (not 1000). cert-sync stays uid 1000 with `ha_ssh_key` and `ha_known_hosts`
mode 0600 owned by 1000:1000 (ssh refuses a key not owned by its user or readable by others). rclone writes
refreshed access tokens back to its config; the mounted file is read-only, so `backup.sh` works on a private copy
in `/tmp` each run. `install.sh` gives the named volumes their owners once (`/data`, `/data/apk`, `/backups` to
10001, `/certs` to 1000) with a one-off root container (`docker compose run --user 0:0 --cap-add CHOWN`). Caddy
runs as root (official image) and reads the 0640 certificate files.

### What was checked on the Mac (2026-10-18)

* `shellcheck` on every `infra/**/*.sh`: clean.
* `podman-compose -f infra/pi/compose.yaml --env-file <filled sample> config`: exit 0.
* `cert-sync` and `backup` images built for linux/arm64 with Podman (not pushed).
* End-to-end rehearsal with Podman: a stand-in Home Assistant sshd with the variant A key below, the cert-sync
  image as uid 1000 with `StrictHostKeyChecking=yes`, the pinned Caddy with `pi/Caddyfile` in front of a stand-in
  server. The first fetch installed both files (0640); `GET /health` through Caddy answered over TLS; a renewed
  certificate was installed and Caddy reloaded through its admin API without a restart; an unchanged certificate
  was left alone; an older certificate and a key that does not match the certificate were refused with the old pair
  kept; TLS 1.1 was refused. **Caddy logged the request headers with `"Authorization":["REDACTED"]` and the token
  never appeared in its log** (SPEC §10.5.2).
* Backup rehearsal with a local rclone remote: upload, `lsf` confirmation by name and size, local deletion only
  after both files were confirmed (D-002); files kept and `last-success` unchanged when the upload failed; the
  leftovers uploaded by the next good run; healthcheck green on a fresh start and after a run, red at 26 h.
* Not checked (needs the real hosts): the Home Assistant add-on's handling of `authorized_keys` options, the
  Gitea workflow (not yet run), pulls from `gitea.lan`, the router forward, Drive.

### Gitea Actions workflow (`.gitea/workflows/build-images.yaml`), not yet run

Same setup as the owner's working example: `runs-on: host`, `sh` steps, `apk add git docker-cli docker-cli-buildx`,
`docker login gitea.lan` with the repository secret `kvitt_cicd` (created by the owner) and `${{ github.actor }}`,
a buildx builder whose `buildkitd.toml` sets `http = true` for `gitea.lan` (created once and reused, so its cache
survives), `actions/checkout@v4` with `set-safe-directory` and `fetch-depth: 0`, the version from the newest
`v1.0.*` git tag plus one, and the git tag pushed after the build. That version is what `deploy.sh` takes.

**Risk: the runner is a Raspberry Pi 3 with 1 GB RAM.** The server image compiles about 232 Rust crates,
aws-lc-sys's C code among them. The workflow passes `--build-arg CARGO_BUILD_JOBS=1`; it takes effect only once
`server/Dockerfile` declares `ARG CARGO_BUILD_JOBS` in its build stage (requested from the server's owner; until
then buildx warns about an unused build argument and cargo uses all four cores, which may run out of memory). The
Dockerfile already keeps the cargo registry and target directory in BuildKit cache mounts, so only the first build
is a full one. The first build's duration on the Pi is unknown (a cold arm64 build takes 48 s on the M4 Mac). If
it fails for memory, add swap on the runner Pi, or build on the Mac with `infra/build-images.sh`.

### Mac fallback: `infra/build-images.sh [tag]`

Builds the same three images for linux/arm64 and pushes them when `infra/secrets/registry.env` exists
(`KVITT_REGISTRY=gitea.lan/jacobh2`, optional `KVITT_REGISTRY_USER` and `KVITT_REGISTRY_TOKEN` with
write:package); otherwise it builds locally and prints the exact push commands. Tag: the short git SHA by default,
plus `latest`. Refuses a dirty tree and does not build while a Gradle build holds the gradle-serial lock. With
Podman (this Mac) it pushes with `--tls-verify=false`; with Docker it creates a buildx builder that allows plain
HTTP to the registry.

### Publishing an APK: `infra/publish-apk.sh`

Version rule (SPEC §10.6): `version_code` = `git rev-list --count HEAD`, `version_name` = `YYYY.MM.DD-<short sha>`
of HEAD's commit date (Europe/Stockholm), passed as `-Pkvitt.versionCode` and `-Pkvitt.versionName`. The image
tags of the Gitea workflow (`v1.0.N`) are separate and say nothing about the APK. The script refuses a dirty tree,
builds `:app:assembleRelease` through `tools/gradle-serial.sh` (JDK 25 on `PATH`), refuses an unsigned APK, and
writes into `infra/pi/out/apk/`: `kvitt-<version_code>.apk`, `kvitt-<version_code>.mapping.txt` (the R8 mapping,
for reading stack traces; never served) and `latest.json` (temp file, then rename); it keeps the newest 5 APKs
with their mappings. Then the owner, on the Mac:

```bash
cd /Users/jhag/projects/kvitt
scp infra/pi/out/apk/* <KVITT_PI_SSH_USER>@<KVITT_PI_HOST>:/opt/kvitt/apk/
ssh <KVITT_PI_SSH_USER>@<KVITT_PI_HOST> /opt/kvitt/install-apk.sh
```

`install-apk.sh` checks the SHA-256 against `latest.json`, copies the APKs into the `data` volume (`/data/apk/`)
and `latest.json` last with a rename, keeps the newest 5 there and prints `GET /apk/latest`.

## Pi: what the owner does

Fill these in first (in `infra/pi/.env` on the Mac; the bundle carries the file to the Pi):

| Placeholder in `infra/pi/.env` | What | Where to find it |
|---|---|---|
| `KVITT_PI_HOST` | LAN address of the Kvitt Pi (give it a static DHCP lease) | ASUS router web UI, LAN, DHCP Server, client list |
| `KVITT_PI_SSH_USER` | Your user on the Kvitt Pi | The user set in Raspberry Pi Imager |
| `HA_HOST` | LAN address of the Home Assistant Pi | Router client list, or Home Assistant, Settings, System, Network |
| `HA_PORT` | SSH port of the SSH add-on (default 22) | Home Assistant, Settings, Add-ons, the SSH add-on, Configuration, Network |
| `HA_USER` | SSH user of the add-on (`root` for "Terminal & SSH"; the configured `username` for "Advanced SSH & Web Terminal") | Same add-on, Configuration |
| `HA_CERT_DIR` | Directory holding `fullchain.pem` and `privkey.pem` on the Home Assistant Pi (`/ssl` on Home Assistant OS) | In the add-on's terminal: `ls -l /ssl` |
| `KVITT_TAG` | Image tag to run: the newest `v1.0.N` the Gitea workflow pushed (or the SHA from `build-images.sh`) | Gitea, the repository, Packages, `kvitt-server` |
| `KVITT_REGISTRY_USER`, `KVITT_REGISTRY_TOKEN` | Only if the Gitea packages are private: a Gitea user and a token with `read:package` | Gitea, Settings, Applications, Generate New Token |
| `KVITT_REGISTRY` | Already `gitea.lan/jacobh2` | |
| `RCLONE_REMOTE`, `RCLONE_FOLDER_ID` | Already `gdrive:` and `1jDp1dGE5R3H2DBcXCqIPN1iWzQnPkdlV` | |

### 1. Provision the Kvitt Pi

Raspberry Pi Imager on the Mac: Raspberry Pi 3, **Raspberry Pi OS Lite (64-bit)**; in its settings set the host
name, your user and password, the network, time zone Europe/Stockholm, and enable SSH with your public key. Boot
it, give it a static DHCP lease in the router, then from the Mac: `ssh <KVITT_PI_SSH_USER>@<KVITT_PI_HOST>`.

### 2. Install Docker Engine on the Pi (docs.docker.com, Debian arm64 repository)

On the Pi:

```bash
sudo apt update && sudo apt install -y ca-certificates curl python3
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc
sudo tee /etc/apt/sources.list.d/docker.sources <<EOF
Types: deb
URIs: https://download.docker.com/linux/debian
Suites: $(. /etc/os-release && echo "$VERSION_CODENAME")
Components: stable
Architectures: $(dpkg --print-architecture)
Signed-By: /etc/apt/keyrings/docker.asc
EOF
sudo apt update
sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
sudo usermod -aG docker "$USER"
exit
```

Log in again; `docker compose version` prints a version and `docker run --rm hello-world` prints
"Hello from Docker!".

### 3. Put the cert-sync key on the Home Assistant SSH add-on

Home Assistant, Settings, Add-ons, your SSH add-on, Configuration, `authorized_keys`: add **one** new entry.
Try variant A first (replace `/ssl` if your `HA_CERT_DIR` differs):

Variant A (restricted, preferred):

```
restrict,command="tar -C /ssl -cf - fullchain.pem privkey.pem" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMiXj2dU8GU0Xmdj91WxLhVpPOI1zRWvBF5h2MbE4S8V kvitt-cert-sync
```

Save, restart the add-on. If the add-on refuses to save or start with it (its Log tab shows an error about the
key), replace it with variant B:

Variant B (plain key):

```
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIMiXj2dU8GU0Xmdj91WxLhVpPOI1zRWvBF5h2MbE4S8V kvitt-cert-sync
```

cert-sync works with both unchanged: it always asks for exactly that `tar` command. Tell the orchestrator which
variant the add-on accepted, so it is recorded here. The private key is
`/Users/jhag/projects/kvitt/infra/secrets/ha_ssh_key` (git-ignored; never paste it anywhere).

### 4. Fill the `.env` and stage the secrets, on the Mac

```bash
cd /Users/jhag/projects/kvitt
cp infra/pi/.env.example infra/pi/.env
open -e infra/pi/.env            # replace every CHANGE_ME (table above), save
mkdir -p infra/pi/secrets
cp infra/secrets/fcm-service-account.json infra/secrets/ha_ssh_key infra/secrets/rclone.conf infra/pi/secrets/
```

`rclone.conf` is already generated from your `rclone authorize "drive"` (remote `[gdrive]`, `type = drive`,
`scope = drive`, the token); the Drive folder id is `RCLONE_FOLDER_ID` in `.env`, not in the conf.
`infra/pi/.env` and `infra/pi/secrets/` are git-ignored.

### 5. Copy the bundle to the Pi and record the Home Assistant host key

On the Mac:

```bash
scp -r infra/pi <KVITT_PI_SSH_USER>@<KVITT_PI_HOST>:kvitt-pi
rm -r infra/pi/secrets           # the originals stay in infra/secrets/
```

On the Pi:

```bash
cd ~/kvitt-pi
ssh-keyscan -p <HA_PORT> <HA_HOST> > secrets/ha_known_hosts
wc -l secrets/ha_known_hosts     # at least 1 line
```

### 6. Install and start

On the Pi:

```bash
cd ~/kvitt-pi && ./install.sh
```

It creates `/opt/kvitt/{secrets,import,apk}`, installs the four secret files (`fcm-service-account.json` 0440
root:10001; `ha_ssh_key`, `ha_known_hosts` 0600 1000:1000; `rclone.conf` 0600 10001:10001), adds `gitea.lan` to
`insecure-registries` in `/etc/docker/daemon.json` (and restarts Docker if that changed), copies `compose.yaml`,
`Caddyfile`, `.env` (0600) and the scripts to `/opt/kvitt`, pulls, starts and waits. Expected end:
`server: healthy`, `cert-sync: healthy`, `caddy: healthy`, a `docker compose ps` table, the line
`GET https://icehack.asuscomm.com:8443/health (via this Pi): {"status":"ok",...}`, then "Kvitt is running.".
Then `rm -r ~/kvitt-pi/secrets` (the script reminds you). Running `install.sh` again is safe.

### 7. Router forward

ASUS router web UI, WAN, Virtual Server / Port Forwarding: add a rule, protocol TCP, external port 8443, internal
IP `<KVITT_PI_HOST>`, internal port 8443; Apply. Then on the phone with Wi-Fi off, open
`https://icehack.asuscomm.com:8443/health` in Chrome: it shows `"status":"ok"` without a certificate warning (yes/no).

### 8. First backup and bootstrap

On the Pi:

```bash
/opt/kvitt/backup-now.sh      # ends with "last-success: <stamp>" and the newest kvitt-*.sqlite.gz and pictures-*.tar.gz on Drive
/opt/kvitt/bootstrap.sh       # first install only: prints the admin invite code, link and expiry
```

### 9. Deploying a new version

After the Gitea workflow pushed `v1.0.N` (or `infra/build-images.sh` printed a tag), on the Pi:

```bash
/opt/kvitt/deploy.sh v1.0.N
```

It backs up first (Drive confirmed) on every deploy, because any tag may carry a migration (SPEC §10.10), sets
`KVITT_TAG`, pulls, starts, waits for `server: healthy` and prints `/health`. If the server does not come up:
`/opt/kvitt/deploy.sh "$(cat /opt/kvitt/previous-tag)" --skip-backup`; if a migration had partially applied,
restore the pre-deploy backup (`infra/RESTORE.md`). A newer bundle with a changed `compose.yaml` or `Caddyfile` is
installed by copying the bundle again (step 5, without the secrets) and running `./install.sh`.

### Fallback: Caddy internal CA (SPEC §10.5.3, not deployed)

Only if cert-sync cannot be made to work. In `/opt/kvitt/Caddyfile` replace the line
`tls /certs/fullchain.pem /certs/privkey.pem` with `tls internal`, then `docker compose restart caddy` in
`/opt/kvitt`. Copy Caddy's root to the Mac once: on the Pi
`docker compose cp caddy:/data/caddy/pki/authorities/local/root.crt /tmp/kvitt_root_ca.crt`, then on the Mac
`scp <KVITT_PI_SSH_USER>@<KVITT_PI_HOST>:/tmp/kvitt_root_ca.crt android/app/src/release/res/raw/kvitt_root_ca.crt`
(a public certificate, committed by an Android agent) and set `kvitt.tls.pinnedRoot=true` in
`android/gradle.properties` (D-082). The root is valid 10 years. Caddy still waits for cert-sync to be healthy,
which needs the two files in the `certs` volume: keep the last fetched pair there, or remove the `cert-sync`
condition from `depends_on` in `/opt/kvitt/compose.yaml`.

### Operations (SPEC §10.10), on the Pi in `/opt/kvitt`

| Task | Command |
|---|---|
| Status | `docker compose ps` |
| Logs | `docker compose logs --tail 100 <caddy, server, cert-sync or backup>` |
| Backup now | `/opt/kvitt/backup-now.sh` |
| Upgrade | `/opt/kvitt/deploy.sh <tag>` |
| Roll back | `/opt/kvitt/deploy.sh "$(cat /opt/kvitt/previous-tag)" --skip-backup` |
| Certificate now | `docker compose exec cert-sync /usr/local/bin/sync.sh` |
| Certificate expiry and issuer | `docker compose exec cert-sync openssl x509 -in /certs/fullchain.pem -noout -enddate -issuer` |
| Extra device invite | `docker compose exec server kvitt-server pair-device --user <user_id>` |
| Memory | `docker stats --no-stream` (server RSS under 100 MB with both phones syncing) |
| Disk | `df -h /` and `docker system df`; SQLite a few MB, pictures under 1 MB, APKs about 20 MB each, 5 kept |
| No token in Caddy's log | `docker compose logs caddy \| grep -c 'kvt_'` prints `0` |
| Restore | `infra/RESTORE.md` |

### Troubleshooting

* `cert-sync` unhealthy, so `caddy` does not start: `docker compose logs cert-sync`. "Host key verification
  failed": redo `ssh-keyscan` (step 5) and run `./install.sh` again. "Permission denied (publickey)": the add-on
  does not have the key (step 3). "did not hold fullchain.pem and privkey.pem": wrong `HA_CERT_DIR`, or `HA_USER`
  cannot read `privkey.pem`.
* Pull fails with "http: server gave HTTP response to HTTPS client": `gitea.lan` is missing from
  `/etc/docker/daemon.json` (`install.sh` adds it; check with `docker info | grep -A3 'Insecure Registries'`).
* Pull fails with "unauthorized": the packages are private; set `KVITT_REGISTRY_USER` and `KVITT_REGISTRY_TOKEN`
  in `~/kvitt-pi/.env` and run `./install.sh` again.
* `install.sh` says `/opt/kvitt/secrets/<file>` is a directory: Docker created it because the file was missing at a
  start; `sudo rmdir` it, put the file in `~/kvitt-pi/secrets/`, run `./install.sh`.