fix: resolve ESP32-S3 linker errors, all boards produce firmware

Three fixes:
- Add .cargo/config.toml with -Tlinkall.x for xtensa target (resolves
  ROM functions, interrupt handlers, memory layout)
- Add integrated-timers feature to embassy-executor for ESP32 boards
  (resolves _embassy_time_schedule_wake)
- Add `use esp_println as _` to pull in defmt global_logger (was being
  stripped as dead code because nothing referenced the crate)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -359,6 +359,8 @@ dependencies = [
  "critical-section",
  "document-features",
  "embassy-executor-macros",
+ "embassy-time-driver",
+ "embassy-time-queue-driver",
 ]
 
 [[package]]