feat(nostr-vpn): package paid-exit seller + web control panel as manifest apps

Phase 1 of docs/nostr-vpn-integration-plan.md's Phase 0->4 plan (seller-side
rootless feasibility already confirmed there). Two apps, one image:

- apps/nostr-vpn: the daemon. Own network namespace (container.network:
  pasta), NET_ADMIN+NET_RAW scoped to that netns, /dev/net/tun, and the
  net.ipv4.ip_forward sysctl via the primitive added in e42bd26. UDP 51822
  (not upstream's default 51820, which collides with archipelago-wg on
  fleet nodes per the Phase 0 log). Seller mode stays off until an operator
  explicitly enables it (paid_exit.enabled defaults to false upstream).
- apps/nostr-vpn-web: the control panel, gated behind 127.0.0.1:38080,
  talking to the daemon only through the shared /data volume (state-file
  status + shelling out to the nvpn CLI) -- no network link between the
  two containers, matching upstream's own umbrel/docker-compose.yml.
- docker/nostr-vpn: upstream's umbrel/Dockerfile, unchanged except for how
  the pinned commit arrives (shallow git fetch of a verified SHA, since
  codeload.github.com archive tarballs 404 from this environment and
  GitHub won't fetch an arbitrary SHA directly). Entrypoint seeds a minimal
  config.toml with the chosen listen_port on first boot only -- every
  AppConfig field is `serde(default = ...)`, confirmed by reading
  nostr-vpn-core directly, so this merges with nvpn's own identity/wallet
  bootstrap instead of needing a generated_secrets entry or full config
  template, and never touches a config that already exists.

Both volumes point at /var/lib/archipelago/nostr-vpn, adopting state from
the old root-mode install. Build and the seed-config path were verified
against the real `nvpn daemon` binary, not just read -- see the plan doc's
Phase 1 log for what that caught (a fabricated commit SHA, the codeload
404, wrong default branch name, and confirming identity/wallet persistence
actually survives container recreation).

Not done here, flagged in the plan doc instead: removing the old root-mode
path (rpc/vpn.rs, rpc/auth.rs's auto-enable-on-login) touches live
onboarding on every node, not just this app -- needs explicit sign-off.
Also missing: a stop-hook/uninstall-guard manifest primitive (doesn't
exist yet -- LifecycleHooks only has post_install/pre_start) for the
collect-due-on-stop and non-zero-wallet uninstall guard, and registry
mirroring + catalog signing (need credentials this pass doesn't have).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/nostr-vpn/manifest.yml

@@ -0,0 +1,119 @@
+app:
+  id: nostr-vpn
+  name: Nostr VPN (paid exit)
+  version: 1.0.0
+  # Pinned commit, not a tag -- upstream has no release tags yet. Re-pin
+  # deliberately in docker/nostr-vpn/Dockerfile's NVPN_COMMIT build arg; see
+  # docs/nostr-vpn-integration-plan.md for the Phase 0 feasibility log this
+  # pin was verified against.
+  upstream:
+    kind: github
+    repo: mmalmi/nostr-vpn
+  description: |
+    Sells spare bandwidth as a Nostr-discovered, Cashu-metered paid exit
+    (github.com/mmalmi/nostr-vpn). Runs rootless in its own network
+    namespace (pasta) -- NET_ADMIN/NET_RAW are scoped to that netns, never
+    the host. Seller mode defaults OFF (upstream's own `paid_exit.enabled`
+    default); turning it on is a separate step (Phase 3 UI, not yet built).
+
+    This replaces the old root-mode integration (image-recipe's
+    nostr-vpn.service running `nvpn daemon` as root, auto-enabled on first
+    login via rpc/auth.rs) that broke the rootless/no-OS-reliance
+    invariant. That old path and its RPC TOML-rewriting code
+    (rpc/vpn.rs::handle_vpn_add_participant) are a separate, higher-risk
+    removal -- not done here, since it's wired into every node's login
+    flow today, not just this app.
+  category: money
+
+  container:
+    build:
+      context: /opt/archipelago/docker/nostr-vpn
+      dockerfile: Dockerfile
+      tag: localhost/nostr-vpn:local
+    network: pasta
+    # Image has no image-level ENTRYPOINT/CMD (see Dockerfile) -- both this
+    # app and nostr-vpn-web point the shared seed-config entrypoint at
+    # different binaries/args.
+    entrypoint: ["/usr/local/bin/archy-nvpn-entrypoint.sh"]
+    custom_args:
+      - /usr/local/bin/nvpn
+      - daemon
+      - --config
+      - /data/config/nvpn/config.toml
+
+  dependencies:
+    - storage: 1Gi
+
+  resources:
+    memory_limit: 256Mi
+
+  security:
+    # NET_ADMIN/NET_RAW: TUN device + the exit forwarding/NAT nvpn installs
+    # itself inside its own netns (nvpn-exit-forward-in/out, nvpn-exit-masq,
+    # the MSS clamp) -- confirmed working rootless in Phase 0 testing, with
+    # no capabilities beyond these two plus the sysctl below. Host iptables
+    # and routes were confirmed untouched.
+    capabilities: [NET_ADMIN, NET_RAW]
+    # false: not verified read-only-root-compatible in Phase 0 testing (the
+    # working run flags there didn't include --read-only). nvpn's own state
+    # (config/identity/wallet) lives on the /data volume either way.
+    readonly_root: false
+    no_new_privileges: true
+    network_policy: isolated
+
+  # Rootless /proc/sys is read-only, so forwarding can only be set at
+  # container-create time via this primitive (added for exactly this app --
+  # see commit e42bd26). nvpn only *reads* ip_forward and writes it when 0,
+  # so setting it here once at create is enough; nvpn's own cleanup path
+  # leaves it alone.
+  sysctls:
+    net.ipv4.ip_forward: "1"
+
+  devices:
+    - /dev/net/tun
+
+  ports:
+    # Paid-exit buyers dial this directly from the open internet to pay for
+    # bandwidth -- it's the whole point of the app, not an admin surface,
+    # and it speaks nvpn's own FIPS UDP wire protocol, not HTTP, so the app
+    # gate cannot front it. 51822, not upstream's default 51820: that
+    # collides with archipelago-wg (kernel WireGuard) on fleet nodes --
+    # found running both side by side in Phase 0 testing.
+    - host: 51822
+      container: 51822
+      protocol: udp
+      auth: none
+      auth_rationale: >-
+        FIPS UDP transport for paid-exit buyers. Anonymous by design (not
+        HTTP), and the seller is off by default (paid_exit.enabled=false)
+        until an operator explicitly turns on selling, so exposure here
+        alone grants no access to anything.
+
+  volumes:
+    # Adopts whatever a node already has under the old root-mode path
+    # (nostr-vpn.service wrote here too) -- an identity, wallet balance, or
+    # pending Cashu credit must survive this migration, not reset.
+    - type: bind
+      source: /var/lib/archipelago/nostr-vpn
+      target: /data
+      options: [rw]
+
+  environment:
+    - NVPN_LISTEN_PORT=51822
+
+  health_check:
+    type: exec
+    endpoint: nvpn status
+    interval: 30s
+    timeout: 10s
+    retries: 3
+
+  metadata:
+    category: money
+    tier: optional
+    author: mmalmi
+    repo: https://github.com/mmalmi/nostr-vpn
+    features:
+      - Sell spare bandwidth as a Cashu-metered Nostr paid exit
+      - Rootless: own network namespace, no host network access
+      - Seller mode off by default