refactor(logger): eliminate logger level factory duplication with generics

[Copilot]

internal/logger/common.go had two structurally identical function pairs (makeLevelLogger/makeServerLevelLogger and newLevelLoggerFuncs/newServerLevelLoggerFuncs) plus two mirrored struct types (levelLoggerFuncs/serverLevelLoggerFuncs), differing only in the presence of a serverID string parameter. Adding a new log level required changes in four places instead of two.

Changes

• logFuncSet[F any] — new generic struct replacing both levelLoggerFuncs and serverLevelLoggerFuncs; holds the info/warn/error/debug quad for any function signature F
• newLogFuncSet[F any] — new generic factory replacing both new*LevelLoggerFuncs bodies; calls makeFunc(level) once per level
• Type aliases — levelLoggerFuncs and serverLevelLoggerFuncs become aliases for their respective logFuncSet instantiations; no call-site changes needed in file_logger.go, markdown_logger.go, or server_file_logger.go
• makeLevelLogger/makeServerLevelLogger removed — inlined into the two thin new* wrappers that now delegate to newLogFuncSet

// Before: two parallel structs + two parallel make* functions + two parallel new* functions

// After: one generic struct + one generic factory
type logFuncSet[F any] struct { info, warn, error, debug F }

func newLogFuncSet[F any](makeFunc func(LogLevel) F) logFuncSet[F] {
    return logFuncSet[F]{
        info:  makeFunc(LogLevelInfo),
        warn:  makeFunc(LogLevelWarn),
        error: makeFunc(LogLevelError),
        debug: makeFunc(LogLevelDebug),
    }
}

// Type aliases preserve existing call sites unchanged
type levelLoggerFuncs       = logFuncSet[func(string, string, ...interface{})]
type serverLevelLoggerFuncs = logFuncSet[func(string, string, string, ...interface{})]

A new log level now requires a single entry in newLogFuncSet instead of four.

[Copilot]

Pull request overview

Refactors the internal logger’s per-level closure wiring to remove duplicated factory/struct patterns by introducing a single generic logFuncSet + newLogFuncSet, while keeping existing call sites unchanged via type aliases.

Changes:

• Introduced generic logFuncSet[F any] to represent the per-level (info/warn/error/debug) function bundle for any signature.
• Added newLogFuncSet generic factory and rewired newLevelLoggerFuncs / newServerLevelLoggerFuncs to delegate to it (removing the duplicated make* helpers).
• Converted levelLoggerFuncs / serverLevelLoggerFuncs to type aliases over logFuncSet[...] so downstream loggers don’t need updates.

Show a summary per file

File	Description
internal/logger/common.go	Consolidates per-level logger closure construction using generics and type aliases to eliminate duplicated implementations.

Copilot's findings

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• Files reviewed: 1/1 changed files
• Comments generated: 1

[lpcox]

@copilot address review feedback

[Copilot]

@copilot address review feedback

Fixed in 0a2ac79. Updated the stale guidance in internal/logger/common.go to reference newLogFuncSet as the centralized place to update per-level bindings.