feat: add lab-rv32i-freertos-sw-timer card

README.md

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+# K14 — Software timer and the timer daemon task
+
+K14 implements a freestanding, non-copyable C++ SoftwareTimer wrapper over
+statically allocated FreeRTOS timers. OneShotTimer and PeriodicTimer encode the
+reload policy in the type. The constructor creates the timer, while start,
+reset, change_period and stop remain explicit commands sent to the timer daemon.
+
+The target experiment starts both timers before the scheduler:
+
+    command acceptance snapshot: callbacks = 0
+    periodic initial period 2:    ticks 2, 4
+    one-shot reset at tick 1:     callback at tick 6, then inactive
+    periodic change at tick 4:    next callback at tick 7
+    periodic stop:                inactive, no fourth callback
+
+The callback checks that its current task is xTimerGetTimerDaemonTaskHandle()
+and that the task name begins with Tmr S. It also records a stack pointer
+different from the verifier task. Timer control blocks, verifier TCB and stacks
+live in .bss; creating both timers leaves the heap unchanged.
+
+## Build
+
+    make check
+
+This runs a host policy test, ABI/storage checks and the deterministic Hazard3
+simulation.
+
+## Debug
+
+    riscv64-unknown-elf-gdb build/task01_sw_timer/prog.elf
+    b software_timer_debug_checkpoint
+    p g_start_commands_accepted
+    p g_callbacks_when_start_returned
+    p g_reset_tick
+    p g_change_tick
+    p g_one_shot_tick
+    p g_periodic_ticks
+    p g_daemon_handle_match
+    p g_daemon_name_match
+    p g_timer_pass
+
+## Lifetime boundary
+
+The timer ID stores a pointer to the typed callback context. Therefore the
+StaticTimer_t storage, wrapper and context must remain alive while a command or
+callback can still be pending. A successful API return proves queue acceptance,
+not callback completion. Timer callbacks execute in the shared daemon task and
+must not block.