Product v2 feature-completion controls

This pass extends Product v2. It does not claim physical sleep, codec or audio qualification. Current output capabilities still come from the platform.

• Audio → Equalizer: enable the existing FFmpeg EQ/limiter, edit five broad

  bands at 60/250/1000/4000/12000 Hz, or reset to flat. Each wheel detent changes the candidate gain by 1 dB, bounded to ±12 dB. Select applies; Back cancels. Values are persisted with the existing settings. Playback uses its existing transactional reconfiguration and rollback. Reset Settings now also removes an active EQ from the running pipeline.

• Audio → Output Details: source codec/bits/rate, decoder/DSP precision and

  the accepted PCM format/rate live in Diagnostics. The accepted PCM container is not proof of the DAC's meaningful payload bits.

• System → Sleep and Quick Settings → Sleep: deliberate sleep is

  distinct from a short Power press, which blanks the display while retaining playback. Playing/buffering refuses sleep with a Pause action explanation. The platform owns admission; current software refuses ordinary deep sleep until same-boot physical qualification is complete. Requested, refused, sleeping, restoring, restored and restore-failed are typed product states. A restored claim additionally needs same_boot=true and kernel_completed=true.

• Bluetooth: codec preference and the observed device codec remain separate.

  A paused player can now select a codec; there is no hidden requirement to use a command-line Stop action. Existing transport and PCM lease guards remain. Optional choices require the current enabled/mutual capability set, discovered read-only when the transport first appears. The saved preference is attempted once per observed connection after playback is paused/stopped; replacement PCM objects do not retrigger it. SBC-only peers still expose their quality setting. SBC quality and LDAC quality/Auto Rate controls use the platform's supported settings. Saved changes say restart required; Diagnostics distinguishes saved values from the current daemon's startup receipt. LDAC quality labels give both rate families: 303/330, 606/660, 909/990 kbps. ABR enabled is a control state, not evidence that adaptation has been observed.

• Diagnostics → Export Diagnostic Report: creates the platform's redacted

  shareable report, then opens Latest Result with its archive path and retrieval instruction. Export Player Data is explicitly a private backup.

• Battery: voltage-derived percentage is labelled Estimated Charge.

  No current, coulomb or battery temperature measurements are invented.

The ready-frame boot handoff and black-frame/backlight-off shutdown sequence from the entry source remain in use. The wheel's input duplicate suppression, acceleration and direction-reset logic is unchanged; the EQ picker uses the existing one-detent value policy. Long modal lists now compute visible rows from the actual description height so the focused row remains on screen.

Validation: cargo fmt --all -- --check, strict workspace clippy and 238 workspace tests passed, including API-boundary, shutdown and input tests. reborn-preview emits 69 deterministic native-resolution cases; the new EQ, long EQ picker, sleep refusal and LDAC settings cases were rendered and viewed. These fixtures are presentation validation, not observations from a device.