tr_config: logColor is a string in TR 5.x; TR_CENTER_HZ keeps the control channels it covers (node-26#45)

Both found on node-002. A boolean logColor made TR 5.2.1 refuse the whole
config (json type_error.302). MTA Zone 2's live control channel is 770.43 MHz,
outside the widest-cover window, so a centre override must be able to pick
which control channels to keep rather than demand all of them fit.

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

drb-edge-node/app/internal/tr_config.py

@@ -224,7 +224,13 @@ def build_tr_config(
         # channels are known here, so the SDR is centred on those. A system
         # whose voice channels sit outside that ~2 MHz loses those calls (TR
         # logs "no source covering" for each) — needs a second source.
-        covered = ccs if center_override else widest_cover(ccs, int(sample_rate))
+        if center_override:
+            half = int(sample_rate) * USABLE_BANDWIDTH_SHARE / 2
+            covered = [c for c in ccs if abs(c - center_override) <= half]
+            if not covered:
+                raise ValueError(f"TR_CENTER_HZ {center_override} covers none of {name!r}'s control channels.")
+        else:
+            covered = widest_cover(ccs, int(sample_rate))
         if len(covered) < len(ccs):
             system["control_channels"] = covered
             logger.warning(
@@ -267,7 +273,7 @@ def build_tr_config(
         # reads the control-channel decode rate from it for the health check.
         "logFile": True,
         "logDir": f"{TR_APP_DIR}/logs",
-        "logColor": False,
+        "logColor": "none",  # TR 5.x: a string ("console"|"none"), not a bool
         # Live audio for Discord: simplestream sends every call's PCM to the
         # edge-node, which follows one talkgroup at a time into PulseAudio.
         "audioStreaming": True,

drb-edge-node/tests/test_trunk_recorder.py

@@ -499,3 +499,10 @@ def test_wide_control_channel_list_is_cut_to_what_one_sdr_covers():
     # MTA Zone 2 (node-002): five control channels spanning 4.15 MHz.
     ccs = [770_156_250, 770_431_250, 773_293_750, 773_843_750, 774_306_250]
     assert tr_config.widest_cover(ccs, 2_400_000) == ccs[2:]
+
+
+def test_center_override_keeps_only_the_control_channels_it_covers():
+    tr, _ = tr_config.build_tr_config(
+        "P25", "MTA", {"control_channels": [770.15625, 770.43125, 773.29375]},
+        **{**TR_KW, "center_override": 770_900_000})
+    assert tr["systems"][0]["control_channels"] == [770_156_250, 770_431_250]