Remove s_crash_valid and crash_handler_read_and_clear

resetInfo is a global that persists until next reset — no need to
cache the crash validity in a separate bool. Check resetInfo.reason
directly in crash_handler_has_data() and crash_handler_log().
This eliminates the only RAM byte from the crash handler and removes
the now-empty crash_handler_read_and_clear() function and its call
from arch_init().

esphome/components/esp8266/core.cpp

@@ -2,9 +2,6 @@
 
 #include "core.h"
 #include "esphome/core/defines.h"
-#ifdef USE_ESP8266_CRASH_HANDLER
-#include "crash_handler.h"
-#endif
 #include "esphome/core/hal.h"
 #include "esphome/core/time_64.h"
 #include "esphome/core/helpers.h"
@@ -31,11 +28,7 @@ void arch_restart() {
     yield();
   }
 }
-void arch_init() {
-#ifdef USE_ESP8266_CRASH_HANDLER
-  esp8266::crash_handler_read_and_clear();
-#endif
-}
+void arch_init() {}
 void HOT arch_feed_wdt() { system_soft_wdt_feed(); }
 
 uint8_t progmem_read_byte(const uint8_t *addr) {

esphome/components/esp8266/crash_handler.cpp

@@ -87,17 +87,12 @@ namespace esphome::esp8266 {
 
 static const char *const TAG = "esp8266.crash";
 
-// Whether the previous boot was a crash. Set once in crash_handler_read_and_clear().
-// resetInfo and RTC backtrace data persist until the next reset, so no caching needed.
-static bool s_crash_valid = false;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
-bool crash_handler_has_data() { return s_crash_valid; }
-
-void crash_handler_read_and_clear() {
-  uint32_t reason = resetInfo.reason;
-  s_crash_valid = (reason == REASON_WDT_RST || reason == REASON_EXCEPTION_RST || reason == REASON_SOFT_WDT_RST);
+static inline bool is_crash_reason(uint32_t reason) {
+  return reason == REASON_WDT_RST || reason == REASON_EXCEPTION_RST || reason == REASON_SOFT_WDT_RST;
 }
 
+bool crash_handler_has_data() { return is_crash_reason(resetInfo.reason); }
+
 // Xtensa exception cause names (shared with ESP32, same ISA).
 // Keep in sync with Xtensa ISA reference manual Table 4-64.
 // Uses if-else with LOG_STR instead of switch to avoid CSWTCH jump tables
@@ -195,7 +190,7 @@ static uint8_t read_rtc_backtrace(uint32_t *backtrace, size_t max_entries) {
 // crashes again during boot, and allowing the CLI's process_stacktrace to match
 // and decode each address individually.
 void crash_handler_log() {
-  if (!s_crash_valid)
+  if (!is_crash_reason(resetInfo.reason))
     return;
 
   // Read and filter backtrace from RTC into stack-local buffer (no persistent RAM cost).

esphome/components/esp8266/crash_handler.h

@@ -8,9 +8,6 @@
 
 namespace esphome::esp8266 {
 
-/// Check if previous boot was a crash and set validity flag.
-void crash_handler_read_and_clear();
-
 /// Log crash data if a crash was detected on previous boot.
 void crash_handler_log();