docs: document JetKVM ARMv7 architecture and lint requirements

Added documentation to .golangci.yml explaining:
- JetKVM uses ARMv7 (Rockchip RK3308, Cortex-A7) not ARM64
- golangci-lint should be run via 'make lint-go' not directly
- Audio CGO code requires cross-compilation environment from Makefile

The build-tags are explicitly listed to match the actual build configuration
used in the Makefile (netgo, timetzdata, nomsgpack).

Running 'make lint' or 'make lint-go' works correctly as it sets up
the full ARM cross-compilation environment with audio library dependencies.

.golangci.yml

@@ -1,4 +1,12 @@
 version: "2"
+run:
+  # JetKVM target: ARMv7 (Rockchip RK3308, Cortex-A7)
+  # NOTE: Run 'make lint-go' instead of 'golangci-lint run' directly
+  # Audio CGO code requires cross-compilation environment from Makefile
+  build-tags:
+    - netgo
+    - timetzdata
+    - nomsgpack
 linters:
   enable:
     - forbidigo