docs: centralize Markdown developer manual

docs/src/development.md

@@ -0,0 +1,42 @@
+# Development and verification
+
+## Fast host checks
+
+```sh
+cargo test --workspace --offline
+cargo clippy --workspace --all-targets --offline --exclude kaptan-geprc-f722-v2 --exclude kaptan-kakute-f7-mini-v3 -- -D warnings
+cargo clippy -p platform-stm32f7 --all-targets --offline -- -D warnings
+cargo fmt --check
+git diff --check
+```
+
+## Target checks
+
+```sh
+cargo check -p kaptan-geprc-f722-v2 --release --target thumbv7em-none-eabihf --offline
+cargo check -p kaptan-kakute-f7-mini-v3 --release --target thumbv7em-none-eabihf --offline
+```
+
+## Strict core coverage
+
+```sh
+scripts/report-test-coverage.sh
+```
+
+The strict gate requires 100% line and branch coverage for `kaptan-math`,
+`kaptan-navigation`, `kaptan-control`, and `kaptan-safety`. It isolates each
+core package's coverage artifacts, unions LCOV source-line records, and uses
+full LLVM source spans to merge generic branch instantiations without lowering
+the gate.
+
+## Simulation acceptance
+
+```sh
+python3 tools/sitl/world-structure-test.py
+python3 -m unittest tools/sitl/test_kaptan_sim.py
+tools/sitl/e2e-smoke.sh
+```
+
+The Docker smoke is intentionally separate from host unit tests because it
+builds the pinned base images, Rust binary, Gazebo plugin, and full loopback
+plant.