Initial public release of WII5 Buoy firmware

Firmware for an autonomous wave-measurement buoy (ATmega2560-based
WII5 v2 board). Reads wave motion from a Sparton AHRS-M1/M2 IMU,
samples GPS and battery state, and reports back over Iridium SBD
satellite telemetry. Originally developed 2012-2024.

This is the first public release. Code, documentation, and field-tested
operating modes (Capture, Sleep, Position, ManualTest, SelfTest,
LowBattery) are licensed under Apache 2.0 — see LICENSE and NOTICE.

See README.md for an overview and build instructions, CONTRIBUTING.md
for how to contribute, and DEPLOYMENTS.md for the field-deployment log.

CODE_OF_CONDUCT.md

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+# Code of Conduct
+
+This project adopts the **Contributor Covenant, version 2.1**, as its code
+of conduct. The full text is published at:
+
+  https://www.contributor-covenant.org/version/2/1/code_of_conduct/
+
+In short: be respectful, be constructive, focus on the technical work.
+Harassment, personal attacks, and discriminatory language are not welcome
+in issues, pull requests, commit messages, code comments, or any other
+project space.
+
+## Reporting
+
+If you experience or witness behaviour that violates this code, please
+report it to the maintainers privately via email (see the contact in the
+project README), or via a private GitHub message to a maintainer. Reports
+will be handled confidentially and in good faith.
+
+## Scope
+
+This code applies to all project spaces — issues, pull requests, the code
+itself, and any related communication channels. It also applies when an
+individual is officially representing the project in public spaces.