Fix builds on ESPHome 2026.10/2026.11 and upgrades from pre-1.3.0 releases

[robsonek]

Three independent fixes, one commit each.

1. wmbus_meter: doesn't load on ESPHome 2026.10

esphome/esphome#19602 turned mqtt.publish into an apply action and removed MQTTPublishAction and mqtt_publish_action_to_code. On 2026.10.0b3 (and dev), every config that uses wmbus_meter therefore fails at validation:

ImportError: cannot import name 'MQTTPublishAction' from 'esphome.components.mqtt'
Component not found: wmbus_meter.

This PR adds an equivalent SendTelegramWithMQTTAction to wmbus_meter/automation.h (guarded by USE_MQTT), along with its own to_code. The action only relies on things that are identical in 2026.9.1, 2026.10.0b3 and dev: MQTT_PUBLISH_ACTION_SCHEMA, MQTTClientComponent::publish(std::string, std::string, uint8_t, bool), TEMPLATABLE_VALUE and register_action(..., synchronous=True). The YAML of wmbus_meter.send_telegram_with_mqtt is unchanged.

2. Builds upgraded from < v1.3.0 fail on a leftover drivers directory

Before v1.3.0, drivers were synced into src/wmbusmeters_drivers. They now go to src/wmbusmeters_generated, and only that directory is pruned. When an existing build directory gets upgraded (for example wM-Bus Gateway 1.1.x to 1.2.x without "Clean Build Files"), the old directory stays behind. ESP-IDF globs src/ recursively, so the build fails:

../src/wmbusmeters_drivers/amiplus.cpp:18:9: fatal error: ../esphome/components/wmbus_common/meters_common_implementation.h: No such file or directory

wmbus_common now removes the legacy directory before syncing drivers.

3. Include alloc_helpers.h directly (ESPHome 2026.11)

helpers.h stops re-exporting alloc_helpers.h in 2026.11.0 (esphome/esphome#20389). quirks.cpp, packet.cpp and component.cpp (wmbus_radio) and extractor.h (panasonic_aquarea) use str_sprintf, format_hex or format_hex_pretty without including it. wmbus_meter.cpp, meter.cpp and records.cpp already include it.

Testing

All builds use the esphome/esphome Docker images and tests/wmbus/sx1276.yaml (esp32) unless noted otherwise.

Scenario	Before	After
2026.9.1	✅	✅
2026.10.0b3	❌ ImportError (MQTT)	✅
dev (2026.11), MQTT action stripped from a throwaway copy to get past (1)	❌ 'str_sprintf' is not a member of 'esphome' in quirks.cpp	✅
dev, full config incl. send_telegram_with_mqtt	❌ (MQTT)	✅
2026.9.1, built once, then a v1.2.5 driver_amiplus.cpp dropped into src/wmbusmeters_drivers/ and rebuilt (no clean)	❌ fatal error above, dir kept	✅, dir removed
tests/panasonic_aquarea/test.yaml on dev	✅	✅
wM-Bus Gateway v1.2.1 package + these components + hydrocalm4/amiplus meters + a wmbus_meter sensor on 2026.10.0b3	❌ (MQTT)	✅

panasonic_aquarea builds on dev even without the extra include, probably because the string extractor template isn't instantiated in the test config. The include follows ESPHome's recommendation to include alloc_helpers.h directly, so it doesn't break once that template is instantiated.

clang-format --dry-run --Werror passes on all touched C++ files.

🤖 Generated with Claude Code

[kubasaw]

Thank you @robsonek! Closing this one, since the three commits went different ways:

1. (wmbus_meter) Use own action for send_telegram_with_mqtt: merged in (wmbus_meter) Fix send_telegram_with_mqtt on ESPHome 2026.10 #79. A follow-up commit there registers send_telegram_with_mqtt the same way mqtt.publish is registered, so it works on both 2026.9 and 2026.10+.
2. Include alloc_helpers.h directly: moved to (wmbus_radio, wmbus_common, panasonic_aquarea) Fix builds on ESPHome 2026.11 #80. On top of it, the log-only hex dumps and the Aquarea error code now go into stack buffers, so wmbus_radio/component.cpp and panasonic_aquarea no longer need alloc_helpers.h. The Aquarea test config was also extended so every extractor gets compiled.
3. (wmbus_common) Remove drivers left in the build dir by pre-1.3.0 releases: not taken over. It only hits a one-off upgrade of an existing build directory, and "Clean Build Files" fixes that. We'd rather not have the component deleting paths in src/ on every build.