docs: plan-era "v1", "Task N" and "Phase N" wording restated as facts (#6277)

The marker list behind the earlier server and web passes did not catch
"for v1", "Task 5", "Phase 2" or "today: Flutter". Those comments now say
what the code does.

Corrected: coverart said "both v1 providers" ship on. There are four
providers (MBCAA, TheAudioDB, Deezer, Last.fm), and Last.fm, which needs a
key, ships off.

Non-comment tokens unchanged against HEAD: 10 Go files, 7 TS/Svelte files.

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

internal/eventbus/eventbus.go

@@ -1,5 +1,6 @@
 // Package eventbus is an in-process publish/subscribe bus for real-time
-// events the server emits to subscribed clients (today: Flutter via SSE).
+// events the server emits to subscribed clients (the web and Android apps,
+// over SSE).
 //
 // Writers (likes handler, requests reconciler, scanner, etc.) call Publish
 // to announce a state change. Each connected SSE client holds a
@@ -13,9 +14,9 @@
 //   - No persistence. A client that connects after an event was emitted
 //     will not see that event. SSE clients are expected to fetch a fresh
 //     snapshot via the normal /api/* endpoints on (re)connect.
-//   - No cross-process broadcast. v1 runs as a single Go binary; a future
-//     multi-instance deployment will need a real broker (NATS / Redis
-//     pub-sub / etc.) but that's out of scope here.
+//   - No cross-process broadcast. Minstrel runs as a single Go binary; a
+//     multi-instance deployment would need a real broker (NATS / Redis
+//     pub-sub / etc.).
 package eventbus
 
 import (