chore: rename project from podpuddle to podsteadr

Renames the repo directory and every podpuddle/PODPUDDLE reference
across code, config, and docs to podsteadr/PODSTEADR (package names,
Docker Compose project/service/volume names, env var names, UI/RSS
strings). Existing Docker volume data (uploaded blobs, mediamtx
recordings, the server's sqlite DB and its nostr identity key) was
migrated to new podsteadr_-prefixed volumes with matching filenames
so it isn't orphaned by the rename.

README.md

@@ -1,4 +1,4 @@
-# podpuddle
+# podsteadr
 
 Self-hosted, nostr-native podcast publishing and livestreaming.
 
@@ -26,7 +26,7 @@ Then open http://localhost:8095, log in with a NIP-07 extension, and follow the
 
 | Service | Host port | Purpose |
 |---|---|---|
-| podpuddle | 8095 | Web UI + API + RSS feeds |
+| podsteadr | 8095 | Web UI + API + RSS feeds |
 | MediaMTX | 1935 | RTMP ingest (OBS) |
 | MediaMTX | 8889 (+8189/udp) | WebRTC/WHIP ingest (browser) |
 | MediaMTX | 8890 | HLS playback |
@@ -54,7 +54,7 @@ Tests: `cd server && npm test`.
 
 ## Data
 
-Everything lives in named docker volumes: `podpuddle-data` (SQLite, server nostr key,
+Everything lives in named docker volumes: `podsteadr-data` (SQLite, server nostr key,
 covers), `mediamtx-recordings` (stream recordings, 7-day retention), `blossom-data`
 (media blobs). `docker compose down` keeps them; `down -v` wipes them.