refactor: relocate MeshCore tools to examples/meshcore/

MeshCore is a protocol implementation ON TOP of DongLoRa, not part of the
dongle itself. Moving it to examples/ makes the separation clear while
keeping it accessible as a real-world usage example.

examples/meshcore/README.md

@@ -0,0 +1,26 @@
+# MeshCore Example
+
+This is a **protocol implementation** built on top of DongLoRa. The DongLoRa
+firmware itself is protocol-agnostic — it just gives you a LoRa radio pipe.
+MeshCore is one of many possible protocols you can run over it.
+
+## What's here
+
+- **meshcore_rx.py** — MeshCore packet decoder, Watchman mesh health reporter
+- **channels.csv** — 276 known MeshCore channels (Public + hashtag channels)
+- **corpus/** — Test vectors for MeshCore packet decoders
+
+## Usage
+
+```sh
+uv run examples/meshcore/meshcore_rx.py [PORT]
+```
+
+Connects to a DongLoRa device, configures the radio for the MeshCore
+frequency/modulation, and decodes received packets in real time.
+
+## Running the test corpus
+
+```sh
+uv run examples/meshcore/corpus/validate.py
+```