ipx-directory: the directory of public podcasts ipx servers share (#204)

A new crate and service, crates/directory, live at ipx-dir.sdf1.net. ipx
servers send the public feeds their people subscribe to (POST /v1/snapshot,
replacing what that token sent before); the directory fetches each feed's
title, artwork, category, description and latest twenty items every six
hours with ipx-feed, and lists them A to Z and by subscribers summed over
every server. It holds metadata only, never a file or a file's address.

Tokens are in its config file as SHA-256 hashes, each ro, rw or rwa, and
the file is read again within a minute of a change, so adding and revoking
one is an edit and nothing else; a revoked token takes its server's counts.
At first they were to come from environment variables, which would have
meant recreating the container to add one. A file that does not load keeps
the tokens as they were.

Every address sent is checked with ipx_feed::url_looks_private, the check
ipx makes before sending, so one server's miss does not publish a paid feed
to every other; an rwa token can remove and block what both miss.

Deployed: ipx-directory in the ipx Arcane project, database ipx_directory
(its own login) on the databases project's Postgres, which db-backup
already covers, and a tunnel route with no Access in front. The store's
tests run on Postgres as well as SQLite when IPX_TEST_DATABASE_URL is set.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -19,6 +19,7 @@ service of the `content` project, beside audiobookshelf, immich and Plex (#208).
 | Database | Postgres 18, database `ipodderx`, login `ipodderx`, on the `postgres` container of the Arcane project `databases` (`192.168.1.130:5433`). The URL is in `ipx.env` beside the compose file (`/mnt/fast/arcane/projects/ipx/ipx.env`, mode 600), passed to the container as `IPX_DATABASE_URL`. A relative `env_file`: Arcane runs compose in its own container, where `/mnt/fast/appdata` does not exist | |
 | Old database | `/mnt/user/ipx/state.db`, SQLite, used until the move to Postgres on 2026-09-18 and kept for rollback | `/data/state.db` |
 | Downloads | `/mnt/user/ipx/downloads` | `/downloads` |
+| Directory | `ipx-directory` in the same project, `192.168.1.130:8100`, public at `ipx-dir.sdf1.net` through the tunnel with no Access in front: tokens are its gate. Config `/mnt/fast/appdata/ipx-directory/directory.toml` (token hashes; Tower's own token in `tower.token` beside it), database `ipx_directory` on the same Postgres, URL in `directory.env` beside the compose file. See [docs/directory.md](docs/directory.md) | `/config/directory.toml` |
 | Web UI | `192.168.1.130:8099`, also `ipodderx.sdf1.net` via a Cloudflare tunnel | `0.0.0.0:8099` |
 | Sign-in via the tunnel | Cloudflare Access app `ipodderx`, with Authentik as its identity provider; see [docs/sso.md](docs/sso.md) | trusts `Cf-Access-Authenticated-User-Email` from `192.168.64.1`, the `ipx_default` gateway (its subnet pinned in the compose file), and only with a valid `Cf-Access-Jwt-Assertion` (`access_team`, `access_aud`) |
 
@@ -54,6 +55,14 @@ docker compose -f /mnt/fast/arcane/projects/ipx/compose.yaml up -d ipx
 docker logs --tail 20 iPX
 ```
 
+The directory is the same, with its own image:
+
+```sh
+docker buildx build -f Dockerfile.directory --tag 192.168.1.130:5000/ipx-directory:latest . --push
+docker compose -f /mnt/fast/arcane/projects/ipx/compose.yaml pull ipx-directory
+docker compose -f /mnt/fast/arcane/projects/ipx/compose.yaml up -d ipx-directory
+```
+
 **Name the service.** A bare `up -d` recreates every container in the project, which once the
 split lands means the frontend and directory too. Run `pull` before `up`, because `up` reuses whatever `latest` the host already has.