slides(tappaas): a slide per lifecycle script; correct the identity claim

install.sh, update.sh and test.sh get one slide each, with the real content of
each — including why a 401 from Cockpit is a passing test and why test.sh uses
curl -s rather than --fail.

Corrects the identity story: Cockpit is not an OIDC client and cannot be
configured into one, so the contract shows identity:accessControl and the demo
slide is honest that Authentik gates the URL while Cockpit still asks for a
local account. Full analysis in the module's DESIGN.md.

slides/tappaas/how-to/new-module/index.md

@@ -176,7 +176,7 @@ That is the whole surface. Everything else is the platform's job.
   "description": "Podman container host — Debian 13 VM with rootless Podman + Cockpit",
   "vmname": "podman", "vmid": 812,
   "dependsOn": ["cluster:vm", "templates:debian", "backup:vm",
-                "network:proxy", "identity:identity"],
+                "network:proxy", "identity:accessControl"],
   "config": {
     "cluster:vm": { "cores": 2, "memory": "2048", "diskSize": "20G",
                     "image": "debian-13-generic-amd64.qcow2" },
@@ -190,15 +190,55 @@ That is the whole surface. Everything else is the platform's job.
 
 ---
 
-## The three scripts, honestly
+## `install.sh` — called once, at add
 
-| Script | Called | Does |
-| --- | --- | --- |
-| `install.sh` | once, at add | For podman: `exec update.sh` — install *is* update here |
-| `update.sh` | every schedule | apt: `podman`, `podman-compose`, `cockpit`, `cockpit-podman`; enable the rootless socket |
-| `test.sh` | on demand + before every update merge | VM reachable · podman present · plugin present · console answers on `:9090` |
+```bash
+#!/usr/bin/env bash
+set -euo pipefail
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+exec "${SCRIPT_DIR}/update.sh" "$@"
+```
 
-If `test.sh` is honest, unattended updates are safe. That is the entire deal.
+By the time it runs, `cluster:vm` has built the VM and `templates:debian` has
+apt-upgraded it and installed the guest agent.
+
+For podman there is nothing install-only — **install *is* update**. Five lines is a
+perfectly good `install.sh`.
+
+---
+
+## `update.sh` — where the work is
+
+Runs on the **mothership**, not on the VM. It:
+
+1. finds the node hosting the VM via `pvesh` — HA-safe, the VM may have moved
+2. resolves the VM's IP through the **Proxmox guest agent**, then waits for SSH
+3. `apt-get install podman podman-compose slirp4netns uidmap cockpit cockpit-podman`
+4. enables the **rootless** `podman.socket`, `loginctl enable-linger`, `cockpit.socket`
+5. records `/etc/tappaas-podman.version`
+6. polls `https://localhost:9090` until the console answers, then prints the URL
+
+Every step is re-runnable: apt is a no-op when current, the marker is overwritten,
+the sockets are `enable --now`. That is what "idempotent" has to mean in practice.
+
+---
+
+## `test.sh` — the one that earns trust
+
+| Check | How |
+| --- | --- |
+| VM reachable | IP resolves via the guest agent |
+| podman installed | version marker + `podman --version` actually runs |
+| plugin present | `dpkg -s cockpit-podman` |
+| console alive | `:9090` answers `200`, `302`, `401` or `403` |
+
+A login page **is** a pass — pre-auth, `401` is the healthy answer.
+
+Prints `N passed, M failed` and exits non-zero on any failure. Note `curl -s`, not
+`--fail`: `--fail` exits 22 on 4xx and would corrupt the `-w '%{http_code}'` we read.
+
+Run on demand, and again before every update is merged. If `test.sh` is honest,
+unattended updates are safe — that is the entire deal.
 
 ---
 
@@ -208,7 +248,7 @@ If `test.sh` is honest, unattended updates are safe. That is the entire deal.
 - OS prep — `templates:debian` did apt + guest agent
 - A VLAN, an interface, DHCP, firewall rules — the zone came with the environment
 - `https://podman.lab1.makerfloss.eu` with a real certificate — `network:proxy`
-- A login — `identity:identity`, so it is your TAPPaaS account, not a local one
+- An access gate — `identity:accessControl`: only the bound groups reach the URL
 - Nightly backup to PBS, scheduled updates, health reporting
 
 A few lines of json bought all of it.
@@ -262,8 +302,9 @@ module-manager module test podman
 Then open **`https://podman.lab1.makerfloss.eu`** — Cockpit, with the Podman page.
 
 - Reachable from the `mgmt` zone only. Not from the internet, by declaration.
-- You log in with your **TAPPaaS identity** — that is what the `identity:identity`
-  dependency buys; no per-VM Linux passwords to hand out.
+- Authentik gates the URL: no `devops` group, no console. Then Cockpit asks *again* —
+  it is not an OIDC client, and a local Unix account is not optional for it.
+- Two logins, honestly. `DESIGN.md` in the repo says what it would take to fix.
 
 ---