refactor!: remove logforth core global logger

[tisonkun]

This closes#214

[Copilot]

Pull request overview

This PR removes the logforth_core “default/global logger” concept and shifts global log crate integration to explicit logforth-bridge-log adapter types (and logforth’s starter-log feature), updating examples, features, and docs accordingly.

Changes:

• Removed core-level global logger APIs (default_logger, set_default_logger, LoggerBuilder::{apply, try_apply}) so LoggerBuilder only constructs Logger instances.
• Refactored the log bridge to expose LogAdapter/OwnedLogAdapter/SharedLogAdapter and removed the previous global setup/try_setup helpers.
• Updated starter_log to register the log crate’s global logger directly using OwnedLogAdapter, and adjusted examples/docs/features to match the new model.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
logforth/src/starter_log.rs	Switches starter to install the log global logger via OwnedLogAdapter instead of relying on a core default logger.
logforth/src/lib.rs	Removes re-exports of core global logger APIs and gates starter_log behind starter-log.
logforth/Cargo.toml	Updates starter-log feature to include an optional log dependency.
examples/src/log_with_logger.rs	Renames example usage from OwnedLogProxy to OwnedLogAdapter.
examples/src/asynchronous.rs	Demonstrates keeping a logger handle (SharedLogAdapter) and registering it with log::set_boxed_logger.
examples/Cargo.toml	Aligns example feature wiring with logforth/starter-log and updates required features for examples.
core/src/logger/mod.rs	Drops re-exports of the removed global logger APIs.
core/src/logger/log_impl.rs	Removes the OnceLock-backed default logger implementation.
core/src/logger/builder.rs	Removes global-logger setup methods and updates doctests to use build().
CHANGELOG.md	Updates breaking-change guidance to reflect “keep a logger handle” instead of using default_logger().flush().
bridges/log/src/lib.rs	Replaces global setup with explicit adapter types (borrowed/owned/shared) and removes setup/try_setup.
appenders/syslog/src/lib.rs	Updates docs to build a logger without relying on removed global logger APIs.
appenders/syslog/Cargo.toml	Removes log dev-dependency (previously used by the docs/example path).
appenders/file/src/rolling.rs	Updates rand trait import in tests (RngExt).
appenders/file/src/lib.rs	Updates docs to build a logger without relying on removed global logger APIs.

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[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 5 comments.