Scaffold NCS firmware project structure

Sets up kvida-os as a freestanding nRF Connect SDK application for the
nRF54L15, pinned to NCS v3.4.0, with a Docker/WSL2 build environment
(toolchain-only image, NCS modules fetched into a separate volume at
first run) and placeholder module directories matching the architecture
described in the kvida meta-repo.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,26 @@
+# Zephyr / nRF Connect SDK
+/build/
+/.west/
+/bootloader/
+/modules/
+/nrf/
+/nrfxlib/
+/zephyr/
+/tools/
+*.o
+*.elf
+*.hex
+*.bin
+*.map
+*.uf2
+
+# Python
+__pycache__/
+*.pyc
+.venv/
+venv/
+
+# OS / editor
+.DS_Store
+Thumbs.db
+.vscode/