Keep the Radio tuning dial silent unless a stream is playing

Releasing the tuning dial always started the chosen station, plus tuning
static, even when nothing was playing. It now follows the Previous/Next
rule: the release plays only if a stream was loading, buffering or playing
when the drag began; otherwise it just selects the station.

The privacy note no longer lists finishing tuning as a way to connect and
now names voice instead, in all locales. Docs, changelog and comments are
tightened to match.

docs/CURRENT-STATE.md

@@ -4702,10 +4702,12 @@ accepted snapshot, and feed telemetry before re-initialization; monotonic
 ownership tokens plus the session boundary keep late callbacks from a retired
 session inert.
 A tuner drag resolves previews against the single accepted snapshot captured at
-pointer-down, even while a newer catalog is admitted. Release starts playback
+pointer-down, even while a newer catalog is admitted. Like Previous/Next,
+release starts playback only if a stream was active when the drag began, and
 only when the current same-ID record still exactly matches the frozen
-presentation and stream metadata; removal or replacement reports the channel as
-unavailable and never silently retargets the drag. A cold degraded fallback may
+presentation and stream metadata; otherwise it just selects the station. Removal
+or replacement reports the channel as unavailable and never silently retargets
+the drag. A cold degraded fallback may
 still populate the directory and globe, but its null accepted generation cannot
 populate or begin the tuner.
 
@@ -4884,7 +4886,7 @@ module. Voice Pause is a playback-only no-op while the layer is disabled; it
 never enables Radio and reports a fulfilled-false pause as failure. A
 newer-response or user-origin Stop still cancels stale handoff work, as do a
 user Pause, a user Previous/Next that only selects another station, and a tuner
-release onto a station the directory no longer has.
+release onto a station the directory removed or changed mid-drag.
 Only a newer user turn or session teardown aborts the complete active-tool set.
 A cancelled turn cannot publish a late Radio playback request. Dedicated Radio
 controls and generic layer-visibility commands both forward cancellation.