fix(config): add RegionCode values 33-37 + fix ITU2_2M label (#3927)

[Yeraze]

Summary

The upstream RegionCode enum (meshtastic/protobufs config.proto) now goes up to 37, but three parallel region lists in MeshMonitor had drifted behind. Devices reporting/configured to a newer region showed no label, weren't selectable in the dropdown, and got no calculated LoRa frequency. This brings all three lists current and fixes an existing mislabel spotted while cross-referencing.

Fixes #3927.

Changes

• REGION_OPTIONS (src/components/configuration/constants.ts) — the region dropdown. Was stopping at 32; adds 33–37 (ITU3_2M, ITU1_70CM, ITU2_70CM, ITU3_70CM, ITU2_125CM) and corrects value 28 from the non-upstream ITU23_2M to the upstream name ITU2_2M.
• regionFrequencyBounds (src/utils/loraFrequency.ts) — a parallel list with the same drift. Adds 33–37 with freqStart/freqEnd taken from firmware RadioInterface.cpp, and fixes the value-28 comment.
• EnumMappings.RegionCode (src/server/services/deviceBackupService.ts) — the backup export name map was even further behind (stopped at 26), so device backups of anything ITU1_2M+ exported a raw number. Completed 27–37.

Sources / verification

• Enum names + values verified against protobufs master config.proto.
• Frequency bounds verified against firmware RadioInterface.cpp (added in meshtastic/firmware#10627, currently on develop / awaiting a firmware release — mirrors the existing "awaiting firmware" EU_874/EU_917 entries). Value 37 band is 220–225 MHz per the proto/firmware (the issue paraphrased 220–222).

Issues Resolved

Fixes #3927

Documentation Updates

No documentation changes needed (region lists are self-describing labels).

Testing

• Full unit suite passes (7946 / 0, success: true)
• TypeScript compiles cleanly
• New constants.test.ts: REGION_OPTIONS covers contiguous values 0–37, no dupes, valid NAME - description labels, value-28 label is ITU2_2M, and 33–37 present
• loraFrequency.test.ts: slot-0 frequency for each new region (e.g. ITU2_70CM 420.0 → 420.125 MHz)
• Manual: in Radio Config, confirm regions 33–37 appear in the dropdown and a device on one shows its label + frequency

🤖 Generated with Claude Code

[github-actions]

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PR Review — fix(config): add RegionCode values 33-37 + fix ITU2_2M label

• Read changed files
• Verify RegionCode values against upstream protobufs
• Review code quality and test coverage
• Post review feedback

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Summary

The changes are correct and well-structured. The enum additions are accurately sourced, the frequency bounds align with the firmware, and the test suite is solid. There is one bug that was missed in this PR.

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Bug: REGION_MAP is incomplete and retains the stale ITU23_2M key

File: src/components/configuration/constants.ts:173-182

The PR correctly fixes REGION_OPTIONS (the dropdown) and EnumMappings.RegionCode (backup export), but REGION_MAP — the reverse lookup used by ConfigurationTab.tsx when parsing a saved LoRa config — was not updated. It still has two problems:

1. Stale key ITU23_2M (line 180) — should be ITU2_2M to match the upstream proto name. A device config restored with the old name will fail to map to value 28.
2. Missing keys 33–37 — if a device config file uses string names like ITU3_2M, ITU1_70CM, etc., the REGION_MAP[lora.region] || 0 fallback in ConfigurationTab.tsx will silently reset the region to UNSET.

-  'ITU23_2M': 28, 'EU_866': 29, 'EU_874': 30, 'EU_917': 31,
-  'EU_N_868': 32
+  'ITU2_2M': 28, 'EU_866': 29, 'EU_874': 30, 'EU_917': 31,
+  'EU_N_868': 32, 'ITU3_2M': 33, 'ITU1_70CM': 34, 'ITU2_70CM': 35,
+  'ITU3_70CM': 36, 'ITU2_125CM': 37

The existing constants.test.ts doesn't cover REGION_MAP at all, so this slipped through. It would be worth adding a test that asserts REGION_MAP is the inverse of REGION_OPTIONS (or at minimum covers the corrected name for 28 and the new 33–37 entries).

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Other observations (non-blocking)

ModemPreset enum in deviceBackupService.ts is truncated at value 8 (SHORT_TURBO, line 149). The MODEM_PRESET_OPTIONS in constants.ts goes up to 13 (NARROW_SLOW). This isn't introduced by this PR, but since the file was touched it's worth noting — backups of devices using presets 9–13 will export a raw number instead of a name. A separate follow-up would be warranted.

Frequency bounds for ITU3_2M (33) — The PR notes it as 144–148 MHz (same as ITU2_2M/28). The label correctly says "144-148 MHz" and the loraFrequency.ts bound is [144.0, 148.0]. The ITU Region 1 2m band (value 27) uses 144–146 MHz. This is accurate per ITU band plans.

Test coverage is good overall:

• constants.test.ts guards against future proto drift with a contiguous-values check — a nice pattern.
• loraFrequency.test.ts includes slot-0 spot checks for all five new regions.
• The test for the ITU2_2M label rename (line 20-23) is well-targeted.

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Verdict

The core data changes are correct and the PR is a clear improvement. The REGION_MAP omission should be fixed before merging — it's the one code path (config restore from YAML/string names) that remains broken for value 28 and the new 33–37 entries.