Safe Mode, crash reports, and a watched main loop

Every build now records at boot which version runs and, after a crash
restart, which one crashed (even across a Rollback). The core dump
summary (task, PC, reason, backtrace) is printed and raised as a
Notification; `crash` shows it later. After 3 crash restarts in a row
the firmware starts in Safe Mode: clock, Wi-Fi, Update Service and Debug
Console only (SafeMode, 2 host tests). A normal restart or a minute up
resets the count.

The main loop is now on the task watchdog (enableLoopWDT): Arduino only
watched core 0's idle task, so a stuck loop hung the device for good.
The Update Service restarts into an installed update by itself if the
main loop hasn't after 90 s.

Debug Builds: `coredump get` and `reset` are answered by the console's
own task; rdbg.py crash decodes the backtrace and rdbg.py coredump runs
esp-coredump, against ELFs archived by version and digest in .pio/elves.

The StorageService mutex is now made in the constructor: Safe Mode never
starts that Service, and `info` crashed on the null mutex, 29 times in a
row before the fix was pushed into Safe Mode over Wi-Fi.

Verified on the device: crash report and full core dump decoded over
Wi-Fi; Safe Mode at exactly 3 crashes, left by `reboot`; a hung loop
caught by the watchdog in 5 s; `reset` from the console task. ADR 0005.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

src/platform/crash_report.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <Print.h>
+
+#include <string>
+
+#include "key_value_store.h"
+
+namespace roro::crash_report {
+
+// First thing at boot: remembers which version runs, and after a crash restart, which version
+// crashed (the one that ran last time, even if a Rollback has switched slots since). Returns how
+// many starts in a row ended in a crash, for Safe Mode.
+int noteBoot(KeyValueStore& store);
+// The device has been up long enough: the crash streak is over.
+void noteStable(KeyValueStore& store);
+
+// The last crash: which firmware, why, and the task, PC and backtrace from the core dump in flash.
+// Decode the backtrace on the PC with scripts/decode_backtrace.sh <version> <addresses>.
+void print(Print& out, KeyValueStore& store);
+// One line for a Notification after a crash restart, e.g. "Restarted after a crash in loopTask".
+std::string headline();
+// Forgets the core dump, so the next crash's is the one kept.
+bool erase();
+
+}  // namespace roro::crash_report