Sync modem presets with current firmware

[powersjcb]

• Replace array-based modem configuration with preset dictionary
• Add missing SHORT_TURBO preset (500kHz, SF=7, CR=5)
• Fix coding rates to match firmware (CR=5 for most, CR=8 for LONG_MODERATE/SLOW)
• Add current_preset property for cleaner access throughout codebase
• Update all references from array indices to string-based preset names
• Add Docker support for testing without local environment setup

This brings the simulator in sync with the current Meshtastic firmware modem presets and improves maintainability with string-based configuration.

[powersjcb]

It looks like the coding rate (CR) was wrong for some of the configs.

Modem Preset Configuration Differences

Preset Name	Index	Parameter	Original (Array-based)	New (Firmware-synced)	Change
SHORT_TURBO	8	Bandwidth	Not Available	500 kHz	✅ Added
		SF	Not Available	7	✅ Added
		CR	Not Available	5	✅ Added
		Sensitivity	Not Available	-121.5 dBm	✅ Added
SHORT_FAST	0	Bandwidth	250 kHz	250 kHz	No change
		SF	7	7	No change
		CR	8	5	⚠️ Fixed
		Sensitivity	-121.5 dBm	-121.5 dBm	No change
SHORT_SLOW	1	Bandwidth	250 kHz	250 kHz	No change
		SF	8	8	No change
		CR	8	5	⚠️ Fixed
		Sensitivity	-124.0 dBm	-124.0 dBm	No change
MEDIUM_FAST	2	Bandwidth	250 kHz	250 kHz	No change
		SF	9	9	No change
		CR	8	5	⚠️ Fixed
		Sensitivity	-126.5 dBm	-126.5 dBm	No change
MEDIUM_SLOW	3	Bandwidth	250 kHz	250 kHz	No change
		SF	10	10	No change
		CR	8	5	⚠️ Fixed
		Sensitivity	-129.0 dBm	-129.0 dBm	No change
LONG_FAST	4	Bandwidth	250 kHz	250 kHz	No change
		SF	11	11	No change
		CR	8	5	⚠️ Fixed
		Sensitivity	-131.5 dBm	-131.5 dBm	No change
LONG_MODERATE	5	Bandwidth	125 kHz	125 kHz	No change
		SF	11	11	No change
		CR	8	8	No change
		Sensitivity	-134.5 dBm	-134.5 dBm	No change
LONG_SLOW	6	Bandwidth	125 kHz	125 kHz	No change
		SF	12	12	No change
		CR	8	8	No change
		Sensitivity	-137.0 dBm	-137.0 dBm	No change
VERY_LONG_SLOW	7	Bandwidth	62.5 kHz	62.5 kHz	No change
		SF	12	12	No change
		CR	8	8	No change
		Sensitivity	-140.0 dBm	-140.0 dBm	No change

[GUVWAF]

Looking good @powersjcb, thanks.
Before merging I would like to keep the original Meshtastic logic only, so when you're ready can you remove the Burning Man-specific things?

It looks like the coding rate (CR) was wrong for some of the configs.

True, actually we changed this somewhere in firmware 2.4 I think. It's a non-breaking change as the CR is in the LoRa header, so you can change it on the fly even.

[GUVWAF]

Hey @powersjcb, hope you had a good time at Burning Man.

If you have time, could you separate the optimizations from the Burning Man-specific changes so we could get this merged?

[zandi]

This PR looks stale, but has a number of changes that look useful for some things I'm wanting to do with Meshtasticator. I can't make any promises, but I'd like to make a PR of just the modem configuration updates, and perhaps other PRs for the other changes. Seem fine?

[GUVWAF]

@zandi yes, I would greatly appreciate that! I guess @powersjcb would be fine with it as well.