tools: config-lint — MCU-load-vs-reserved-memory gate (0x40000 brick class)

The c8a3 brick was a memory-map fault no behavioural sim can catch: a
boot-loaded coprocessor firmware dropped at 0x40000, which is a reserved-memory
carve-out on Thunder-Boot boards but plain kernel RAM on ours. config-lint is
the static gate for it — parse the rkbin loader .ini for every LOADERn=Hpmcu
LOAD_ADDR, parse the target devicetree for reserved-memory ranges, fail if any
MCU load lands outside a reservation.

Tests encode the brick as a regression against the REAL Thunder-Boot .ini
(Hpmcu@0x40000): fails with no rtos@40000 node, passes once reserved; our
board's non-TB loader (no boot-loaded MCU) always passes. 6/6 green; CLI
verified against the on-disk rkbin .ini files.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017wB8KB3MMQztRDXCMCkPrf

README.md

@@ -83,7 +83,7 @@ patches/    the vendor-SDK delta (mirrors flare-edge/sdk-patches until it moves
 build/      the hermetic image-build wrapper (kernel → rootfs → image), incremental.
 ci/         CI: patches-still-apply, host tests, coverage, benchmarks.
 docs/       architecture + ADRs (decisions/).
-tools/      dev tooling.
+tools/      dev tooling. config-lint: static target-config gates (MCU-load-vs-reserved-memory — the 0x40000 brick class).
 ```
 
 ## Principles