feat: publish FreeRTOS C FC08 card

README.md

@@ -0,0 +1,45 @@
+# FC08 — mutexes and priority inheritance
+
+This card is a deterministic Hazard3/RV32I experiment for Chapter 8 of the
+FreeRTOS Kernel Book. It proves the mechanism, not only the final value.
+
+```text
+Low p1 owns mutex
+  → High p3 blocks on the mutex
+  → Low effective priority becomes 3
+  → Medium p2 is Ready but does not run
+  → Low gives the mutex
+  → High acquires before Medium runs
+  → Low returns to priority 1
+```
+
+Only public FreeRTOS APIs are used for acceptance assertions. The internal
+`uxBasePriority` and `uxPriority` fields are shown as debugger evidence, not
+as application dependencies. No manual `vTaskPrioritySet` substitutes for
+priority inheritance.
+
+## Build and evidence
+
+```sh
+make task1
+make host-test
+make check-abi
+make sim
+make check-determinism
+```
+
+The final verifier checks the real mutex holder, effective priorities, public
+task state, three distinct task stacks, protected-resource invariant, exact
+event order and a stable digest from three clean simulator processes.
+
+## Interactive views
+
+- A2 — mutex, owner, waiters and protected resource;
+- A4 — deterministic task topology;
+- A5 — complete inheritance and hand-off sequence;
+- A6 — mutex ownership and effective-priority states;
+- A7 — handles, stacks, public observations and TCB debugger evidence;
+- A8 — critical section, scheduler suspension, mutex and gatekeeper choices.
+
+Source basis: FreeRTOS Kernel Book, Chapter 8. No source example is copied
+verbatim.