logf v2.0.0-beta.2

Changes since beta.1:
- Contextless logging: Debugx, Infox, Warnx, Errorx — no ctx parameter
- Nil context support: all methods accept nil ctx (treated as context.Background())
- Test coverage improved from 86.6% to 92.5%

logf v2.0.0-beta.1

First beta of logf v2 — a complete rewrite of the logging pipeline.

Breaking changes from v1:
- Module path: github.com/ssgreg/logf/v2
- Logger API now requires context.Context as first argument
- Field encoder interfaces simplified (removed rare types)
- SlabWriter uses builder pattern instead of functional options
- Removed BufferedWriter (replaced by SlabWriter)

New features:
- Context-aware fields (logf.With(ctx, ...))
- Native slog bridge (logger.Slog())
- Router for multi-destination logging
- SlabWriter with async slab-based I/O
- WriterSlot for lazy destination initialization
- Text encoder with colored console output
- JSON/Text encoder builders
- LoggerBuilder (NewLogger().Build())
- logfc package (logger-in-context)
- Group fields and WithGroup
- WithName for named loggers

Performance:
- 32% faster than zap and zerolog on real file I/O (6 fields)
- With() 7.6× faster than zap, WithGroup() 20× faster
- p99 latency 43µs under I/O pressure (vs zap 56µs, slog 17.9ms)
- Zero-alloc hot path (except variadic []Field slice)

refactor: eager copy in slice field constructors

new: added unit test for field accept method

new: logfc: add WithLevel

Merge pull request #18 from ssgreg/feature/with-level

add: WithLevel to stack additional level checker

Merge pull request #17 from ssgreg/new-add-go-action

Create go.yml

Merge pull request #15 from pamburus/feature/field-encoder

fix: add missing EncodeFieldStrings to FieldEncoder

Merge pull request #11 from pamburus/feature/level

new: text marshaling support for level

Merge pull request #10 from ssgreg/feature/ext-error-encoder

add: error encoder with options allowing to configure vebose field