Add configurable timezone support with DST handling

[Copilot]

Timezone was hardcoded to Central European Time (index 0). This adds configurable timezone selection with 10 major timezones supporting automatic DST transitions.

Changes

Timezone Definitions (TimeClientHelper.cpp)

• Extended from 2 to 10 timezones: Central/Eastern/Western EU, US Eastern/Central/Mountain/Pacific, Australian Eastern, Japan, China
• All include proper DST rules (transition dates, times, UTC offsets)
• Variable naming improved: CST_CHINA instead of CST_CN to avoid confusion with US Central Standard Time

Configuration API (TimeClientHelper.cpp/hpp)

• Added setTimezoneIndex(int) / getTimezoneIndex() with bounds validation
• Global _selectedTimezoneIndex stores active selection (default: 0)

Runtime Integration (Timer.cpp)

// Before: hardcoded to index 0
time_t t = getTimeFor(0, &tcr);

// After: uses configured timezone
time_t t = getTimeFor(getTimezoneIndex(), &tcr);

Persistent Configuration (PoolController.cpp/hpp)

• Added HomieSetting<long> timezoneSetting_ to PoolControllerContext class with validator [0, getTzCount())
• Applied in setupHandler() via setTimezoneIndex(this->timezoneSetting_.get())
• Integrated with main-v3 refactored codebase structure

MQTT Runtime Control (OperationModeNode.cpp/hpp)

• Property timezone (integer 0-9, settable) - runtime override
• Property timezone-info (string, read-only) - displays current timezone name
• Note: MQTT changes are temporary; persistent config requires updating HomieSetting

Usage

Persistent (survives reboot):

{ "timezone": 3 }  // US Eastern

Runtime via MQTT:

homie/device-id/operation-mode/timezone/set → "3"
homie/device-id/operation-mode/timezone-info → "US Eastern"

Backward Compatibility

Defaults to index 0 (Central European Time) - existing deployments unchanged.

Integration with main-v3

This PR is based on the main-v3 branch which includes a major refactoring of the codebase. The timezone configuration has been successfully integrated with the new PoolController structure:

• Timezone setting is now part of PoolControllerContext class
• All functionality preserved and working with refactored architecture
• Configuration moved from main.cpp to PoolController.cpp/hpp

Original prompt

Wie könnte am besten die Zeitzone konfigurierbar gemacht werden? Damit alle wichtigen Zeitzone inklusive Sommerzeit-Umschaltung auswählbar sind?

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[Copilot]

Pull request overview

This PR adds configurable timezone support with automatic DST handling to replace the hardcoded Central European Time configuration. The implementation allows both persistent configuration via Homie settings and runtime changes via MQTT.

Changes:

• Extended timezone definitions from 2 to 10 major timezones with proper DST rules
• Added timezone selection API with validation and persistent storage
• Integrated MQTT properties for runtime timezone control and information display

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/TimeClientHelper.cpp	Extended timezone definitions to 10 zones and implemented timezone selection API
src/TimeClientHelper.hpp	Added function declarations for timezone getter/setter
src/Timer.cpp	Changed from hardcoded timezone index to dynamic timezone retrieval
src/main.cpp	Added HomieSetting for timezone with validation and applied configuration in setup
src/OperationModeNode.hpp	Added property constants for timezone and timezone-info
src/OperationModeNode.cpp	Implemented MQTT properties for runtime timezone control
platformio.ini	Updated library dependencies and platform version
docs/users-guide.md	Documented timezone configuration options and usage
README.md	Added timezone feature to feature list
_codeql_detected_source_root	CodeQL configuration file

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[Copilot]

The variable name CST_CN conflicts with the US Central Standard Time abbreviation 'CST' defined on line 35. Consider renaming to 'CST_CHINA' or 'CN_CST' to avoid confusion.

Suggested change

	TimeChangeRule CST_CN = {"CST", First, Sun, Mar, 0, 8 * 60}; // UTC + 8 hours
	Timezone China(CST_CN, CST_CN);
	TimeChangeRule CST_CHINA = {"CST", First, Sun, Mar, 0, 8 * 60}; // UTC + 8 hours
	Timezone China(CST_CHINA, CST_CHINA);

[Copilot]

Fixed in commit 57bbf48. Renamed to CST_CHINA to avoid confusion with US Central Standard Time.

[Copilot]

Corrected 'ESP826' to 'ESP8266' in the comment.

Suggested change

	ESP32Async/ESPAsyncTCP @ ^2.0.0 ; TCP-Layer für ESP826
	ESP32Async/ESPAsyncTCP @ ^2.0.0 ; TCP-Layer für ESP8266

[Copilot]

Fixed in commit 57bbf48. Corrected ESP826 to ESP8266.

[Copilot]

This comment explains a user-facing behavior but appears in code that won't be visible to end users. Consider moving this information exclusively to user documentation (where it already exists in users-guide.md) to avoid maintenance duplication.

Suggested change

	// Note: This is a runtime change. To persist across reboots, update the
	// 'timezone' HomieSetting in the configuration file.
	retval = true;
	} else {
	Homie.getLogger() << cIndent << F("✖ Invalid timezone index: ") << tzIndex << endl;
	retval = false;
	}
	// Note: This only updates the timezone at runtime; persistence is handled via configuration.
	retval = true;
	} else {
	Homie.getLogger() << cIndent << F("✖ Invalid timezone index: ") << tzIndex << endl;
	retval = false;
	}

[Copilot]

Fixed in commit 57bbf48. Simplified the comment while keeping brief documentation reference.

[stritti]

Kannst du die merge-Konflikte bitte lösen.

[Copilot]

Kannst du die merge-Konflikte bitte lösen.

Merge-Konflikte gelöst in commit 47bb7f0. Die Timezone-Unterstützung wurde erfolgreich in die neue PoolController-Struktur integriert.