feat: add 3.3GHz SX33 VTX frequency group support with IRC TRUMP protocol

[devin-ai-integration]

Summary

Adds a new 3.3 GHz frequency group (FREQUENCYGROUP_3G3) for the SX33 video transmitter using IRC TRUMP protocol. This includes:

• Frequency table: 5 bands (A–E) × 8 channels, covering 3200–3700 MHz, plus power levels 25/2000/5000 mW (vtx_string.c/h)
• TRAMP driver integration: band/channel→frequency lookup, OSD info, and power metadata for 3.3 GHz in vtx_tramp.c/h
• MSP commands: MSP2_INAV_VTX_TABLE_CUSTOM (0x2F00) to read the table, MSP2_INAV_SET_VTX_TABLE_CUSTOM (0x2F01) to set band/channel/power and switch to the 3.3 GHz frequency group
• Logic condition: LOGIC_CONDITION_SET_VTX_CUSTOM_SLOT (57) for in-flight channel switching via programmable logic, encoding slot as (band-1)*8 + channel with power index in operandB

A companion configurator PR adds the UI (Load Grid button, vtx_table_sx33.json, MSP handling).

Review & Testing Checklist for Human

• Verify frequency table values match actual SX33 hardware specification — all 40 frequencies are hardcoded and cannot be validated without the SX33 datasheet. Incorrect values would tune the VTX to wrong frequencies.
• MSP OUT handler hardcodes magic numbers — fc_msp.c writes 5, 8, 3, 25, 2000, 5000 as literals instead of referencing VTX_STRING_3G3_* defines. If the table dimensions change, these will silently diverge.
• OSD band/channel index bounds — impl_GetOsdInfo accesses vtx3G3BandNames[vtxState.request.band] without bounds checking. If band > 5, this is an out-of-bounds read. (Same pre-existing risk exists for 1.3/5.8 GHz paths, but worth noting.)
• SET_VTX_TABLE_CUSTOM unconditionally sets frequencyGroup = FREQUENCYGROUP_3G3 — there is no way to revert to 5.8 GHz via this command path. Confirm this is intentional.
• Build and flash to SPEEDYBEEF405WING — this code has not been compiled. Verify it builds cleanly for the target and test VTX communication with an SX33 transmitter.

Notes

• The MSP SET command (0x2F01) is named "SET_VTX_TABLE_CUSTOM" but it actually sets a single band/channel/power slot, not a full table. The naming may be confusing for future maintainers.
• LOGIC_CONDITION_SET_VTX_CUSTOM_SLOT hardcodes the max power check (operandB <= 3) instead of using VTX_TRAMP_3G3_MAX_POWER_COUNT.
• No vtx3G3_Freq2Bandchan() reverse-lookup function is provided (unlike 5.8 GHz which has vtx58_Freq2Bandchan). This may be needed later if frequency-based channel identification is required.

Link to Devin session: https://app.devin.ai/sessions/93535a1b2e7847b9b23a2e1396a0bcb2
Requested by: @mailform2022

[devin-ai-integration]

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