tools: cull to a minimal user-facing set

Reduce tools/ to the four scripts an outside contributor needs: build,
verify, flash, and size-profile. Drop maintainer-only workflow scripts
(sibling-repo pulls, firmware-archive auto-commit, version tagging),
broken stubs (doxygen.sh, variables.sh), and the entire tools/2024/
directory.

tools/2024/ included a 647 KB Arduino.tar.gz bundling 20 third-party
Arduino libraries (RadioHead = GPLv2, TinyGPSPlus = LGPL, etc.) without
per-library attribution in NOTICE; a 503 KB GPL avrdude.conf; the GPL
Optiboot bootloader hex; and pre-built firmware/test binaries. Users
install the libraries via Arduino Library Manager (per README), use the
system avrdude, and reproduce the firmware from source.

README.md: add EEPROMEx to the library list (used by WII5Config /
WII5Sh3dConfig); note that RadioHead is GPLv2 dual-licensed and only
LoRa builds (-DWII5_RADIO_LORA) link it.

CONTRIBUTING.md: replace the dead tools/upload.sh reference with the
generic *.local.sh pattern.

Kept: build_local.sh, verify.sh, icsp.sh, memory.pl.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -61,7 +61,12 @@ script's preamble for the variables it expects. Copy any of them to
 Library dependencies (install via Arduino Library Manager or
 `arduino-cli lib install`): TimeLib, RTClib, elapsedMillis, TinyGPSPlus,
 AvgStd, IridiumSBD, OneWire, DallasTemperature, SDBlock, CRC32,
-PushButton, MemoryFree, LowPower, RadioHead.
+PushButton, MemoryFree, LowPower, EEPROMEx, RadioHead.
+
+RadioHead is dual-licensed GPLv2 / commercial. The default ATmega2560
+build does not link RadioHead; only LoRa-enabled builds
+(`-DWII5_RADIO_LORA`) do, and binaries distributed from such builds
+inherit GPLv2 terms.
 
 ## Architecture
 
@@ -106,8 +111,9 @@ WII5*.{h,cpp}         Firmware source (board root, see Architecture)
 WII5_board_v2.h       Pin/peripheral map for the WII5 v2 board
 doc/                  Design notes, command reference, hardware schematics
 test/                 Smaller per-subsystem test sketches
-tools/                Build, flash, and version helper scripts (env-var
-                      driven; copy to *.local.sh to set local defaults)
+tools/                Build, flash, and size-profile helper scripts
+                      (env-var driven; copy to *.local.sh to set local
+                      defaults)
 ```
 
 ## Contributing