[feat](trx-rs): remove MARINE mode (superseded by virtual channels)

MARINE was a composite mode that ran both AIS and VDES decoders
simultaneously. It is now fully replaced by allocating two virtual
channels — one tuned to the AIS frequencies and one to VDES — each
decoded independently.

- trx-core/state: remove RigMode::MARINE variant
- trx-protocol/codec: remove MARINE parse/serialize
- trx-backend-ft817: remove MARINE from unsupported-mode guard
- trx-backend-ft450d: remove MARINE from FM CAT code mapping
- trx-backend-soapysdr: remove MARINE from bandwidth table, supported
  modes list, AIS channel activity check, parse_rig_mode, vchan_impl
  bandwidth table, demod selection, dsp/channel bandwidth / sample-rate
  / IQ-tap guards
- trx-server/audio: remove MARINE from AIS and VDES decoder activation
- trx-server/rig_task: remove MARINE from audio-streaming mode list
- trx-server/main: remove MARINE from bandwidth table, mode parser,
  VDES channel subscription match
- app.js: remove isMarineMode(), MARINE entry in MODE_BW_SPECS, MARINE
  bandwidth specs block in visibleBandwidthSpecs(), MARINE from
  decoder status mode lists, MARINE BW-edge drag guard

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Signed-off-by: Stan Grams <sjg@haxx.space>

src/trx-server/trx-backend/trx-backend-soapysdr/src/demod.rs

@@ -156,7 +156,7 @@ impl Demodulator {
             RigMode::AM => Self::Am,
             RigMode::FM => Self::Fm,
             RigMode::WFM => Self::Wfm,
-            RigMode::AIS | RigMode::VDES | RigMode::MARINE => Self::Fm,
+            RigMode::AIS | RigMode::VDES => Self::Fm,
             RigMode::CW | RigMode::CWR => Self::Cw,
             RigMode::DIG => Self::Passthrough,
             // VHF/UHF packet radio (APRS, AX.25) is FM-encoded AFSK.

src/trx-server/trx-backend/trx-backend-soapysdr/src/dsp/channel.rs

@@ -127,7 +127,7 @@ fn default_bandwidth_for_mode(mode: &RigMode) -> u32 {
         RigMode::FM => 12_500,
         RigMode::WFM => 180_000,
         RigMode::AIS => 25_000,
-        RigMode::VDES | RigMode::MARINE => 100_000,
+        RigMode::VDES => 100_000,
         RigMode::Other(_) => 3_000,
     }
 }
@@ -199,7 +199,7 @@ impl ChannelDsp {
 
         let target_rate = match mode {
             RigMode::WFM => audio_bandwidth_hz.max(audio_sample_rate.saturating_mul(4)),
-            RigMode::VDES | RigMode::MARINE => audio_sample_rate.max(96_000),
+            RigMode::VDES => audio_sample_rate.max(96_000),
             _ => audio_sample_rate.max(1),
         };
         let decim_factor = (sdr_sample_rate / target_rate.max(1)).max(1) as usize;
@@ -466,7 +466,7 @@ impl ChannelDsp {
             self.scratch_decimated
                 .reserve(capacity - self.scratch_decimated.capacity());
         }
-        if matches!(self.mode, RigMode::VDES | RigMode::MARINE) && self.iq_tx.receiver_count() > 0 {
+        if matches!(self.mode, RigMode::VDES) && self.iq_tx.receiver_count() > 0 {
             self.scratch_iq_tap.clear();
             if self.scratch_iq_tap.capacity() < capacity {
                 self.scratch_iq_tap

src/trx-server/trx-backend/trx-backend-soapysdr/src/lib.rs

@@ -68,7 +68,7 @@ impl SoapySdrRig {
         match mode {
             RigMode::LSB | RigMode::USB | RigMode::DIG => 3_000,
             RigMode::PKT | RigMode::AIS => 25_000,
-            RigMode::VDES | RigMode::MARINE => 100_000,
+            RigMode::VDES => 100_000,
             RigMode::CW | RigMode::CWR => 500,
             RigMode::AM => 9_000,
             RigMode::FM => 12_500,
@@ -229,7 +229,6 @@ impl SoapySdrRig {
                     RigMode::FM,
                     RigMode::AIS,
                     RigMode::VDES,
-                    RigMode::MARINE,
                     RigMode::DIG,
                     RigMode::PKT,
                 ],
@@ -367,7 +366,7 @@ impl SoapySdrRig {
         let Some((ais_a_idx, ais_b_idx)) = self.ais_channel_indices else {
             return;
         };
-        let enabled = matches!(self.mode, RigMode::AIS | RigMode::MARINE);
+        let enabled = matches!(self.mode, RigMode::AIS);
         let dsps = self.pipeline.channel_dsps.read().unwrap();
         for idx in [ais_a_idx, ais_b_idx] {
             if let Some(dsp_arc) = dsps.get(idx) {

src/trx-server/trx-backend/trx-backend-soapysdr/src/vchan_impl.rs

@@ -48,7 +48,7 @@ fn default_bandwidth_hz(mode: &RigMode) -> u32 {
         RigMode::FM => 12_500,
         RigMode::WFM => 180_000,
         RigMode::PKT | RigMode::AIS => 25_000,
-        RigMode::VDES | RigMode::MARINE => 100_000,
+        RigMode::VDES => 100_000,
         RigMode::Other(_) => 3_000,
     }
 }