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.

scripts/e2e.mjs

@@ -10,12 +10,12 @@ import { createHash } from 'node:crypto';
 import { existsSync, readFileSync, writeFileSync } from 'node:fs';
 import { finalizeEvent, generateSecretKey } from '../server/node_modules/nostr-tools/lib/esm/pure.js';
 
-const BASE = process.env.PODPUDDLE_URL ?? 'http://localhost:8095';
+const BASE = process.env.PODSTEADR_URL ?? 'http://localhost:8095';
 const BLOSSOM = process.env.BLOSSOM_URL ?? 'http://localhost:8098';
 
 // Persist the test identity across runs — the first pubkey to log in becomes
 // admin, so reruns must reuse it for the settings test to pass.
-const KEY_FILE = '/tmp/podpuddle-e2e-key';
+const KEY_FILE = '/tmp/podsteadr-e2e-key';
 let sk;
 if (existsSync(KEY_FILE)) {
   sk = Uint8Array.from(Buffer.from(readFileSync(KEY_FILE, 'utf8').trim(), 'hex'));
@@ -89,7 +89,7 @@ ok('podcast created', podcast.status === 201 && podcast.json.id);
 const podcastId = podcast.json.id;
 
 // ---- blossom upload (BUD-02, signed like the browser would) ----
-const media = readFileSync(process.env.TEST_MP4 ?? '/tmp/podpuddle-test.mp4');
+const media = readFileSync(process.env.TEST_MP4 ?? '/tmp/podsteadr-test.mp4');
 const sha256 = createHash('sha256').update(media).digest('hex');
 const now = Math.floor(Date.now() / 1000);
 const auth24242 = finalizeEvent(