docs(transistor): thicken podcast hosting skill against current API research

Full skill-builder rebuild of transistor per issue #407:

- scripts/transistor (renamed from transistor-cli): 19 commands covering the
  verified API surface - user probe (GET /v1; the /v1/user route does not
  exist), shows/episodes with corrected pagination[page]/pagination[per],
  the dedicated episode publish endpoint (PATCH /v1/episodes/:id/publish
  with episode[status]=draft|scheduled|published), authorize-upload flow,
  the three real analytics routes with downloads[] array summing,
  subscriber management incl. batch, and webhooks. Write bodies are
  form-encoded bracket keys exactly as documented; dry-run plans carry
  method/path/params/body; publish guard refuses audio-less episodes.
  Fixed stale claims: /analytics/show -> /v1/analytics/..., totals ->
  downloads arrays, pagination[limit] -> pagination[per], user email ->
  name/time_zone, dropped invented episodes_count/subscribers_count and
  POST /v1/shows (show creation is dashboard-only).
- scripts/test_transistor.py: 50 offline tests (pytest + unittest green,
  proxy-trap clean) covering help, argument errors, dry-run plans, canned
  JSON:API compound-document parsing (data/attributes/relationships/
  included[]), write-path body shapes, publish guard, create->audio->
  publish pipeline, and HTTP error signatures.
- references/: auth+JSON:API envelope with jq patterns, endpoint catalog,
  publish lifecycle with documented request/response shapes, gotchas
  field guide + worked recipes; all cited to live-verified sources.
- evals/evals.json: 8 schema-v1 cases incl. two should-not-trigger probes.
- SKILL.md rewritten (308 lines), README refreshed, root README blurb and
  generated catalogs synced (marketplace.json + llms.txt descriptions).

Publish-body shape reconciliation: the contract's data.id+data.type JSON:API
PATCH premise was falsified by current official docs (verified 2026-08-29)
and the flimzy/transistor Go SDK; implemented reality escalated in handoff
(see library/transistor-api-facts.md).

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

.claude-plugin/marketplace.json

@@ -1299,7 +1299,7 @@
         "./transistor"
       ],
       "strict": false,
-      "description": "Manage Transistor.fm podcast hosting from the terminal: view shows, list episodes, check analytics, and get subscriber counts. Use when the user mentions Transistor, podcast hosting, podcast analytics, show management, or episode tracking."
+      "description": "Operate Transistor.fm podcast hosting from the terminal: verify API access, browse shows and episodes with JSON:API-aware output, run the episode publish lifecycle (create draft, attach audio, publish or schedule via the dedicated publish endpoint), pull download analytics, and manage private podcast subscribers and webhooks. Use when the user mentions Transistor, Transistor.fm, podcast hosting, episode publishing, private podcast subscribers, or podcast download analytics. Do not use this skill for other podcast hosts (Buzzsprout, Libsyn, Megaphone, Spotify for Creators), for editing or producing audio, or for feed/RSS parsing — the bundled CLI manages a Transistor account through its v1 API and cannot create new shows (dashboard-only)."
     },
     {
       "name": "travel-guide",