otelfiber: Add LoggerProvider support

[Copilot]

OpenTelemetry defines a LoggerProvider interface but otelfiber had no support for it. This adds WithLoggerProvider config option and automatic per-request log record emission correlated with the active trace.

Changes

• config.go: Added LoggerProvider otellog.LoggerProvider field + WithLoggerProvider(otellog.LoggerProvider) Option. Falls back to global logger provider when unset (consistent with tracer/meter behavior).
• fiber.go: Creates a logger at middleware init; emits one structured log record per request after response processing. Severity is derived from HTTP status: Info (2xx/3xx), Warn (4xx), Error (5xx). Log record attributes: http.request.method, http.route, http.response.status_code, url.path.
• otel_test/fiber_test.go: Tests for record emission, severity mapping (4xx/5xx), and skip-via-Next behavior using an in-memory sdklog.Processor.
• README.md: Documents WithLoggerProvider in the config table and adds a usage example.
• go.mod: Adds go.opentelemetry.io/otel/log v0.17.0 (runtime) and go.opentelemetry.io/otel/sdk/log v0.17.0 (test).

Usage

lp := sdklog.NewLoggerProvider(sdklog.WithProcessor(yourExporter))
app.Use(fiberotel.Middleware(fiberotel.WithLoggerProvider(lp)))

Each request emits a log record such as:

severity: INFO
body:     "GET /users/:id"
attributes:
  http.request.method:      GET
  http.route:               /users/:id
  http.response.status_code: 200
  url.path:                 /users/42

Original prompt

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This section details on the original issue you should resolve

<issue_title>🚀 [Feature]: Add LoggerProvider to otelfiber</issue_title>
<issue_description>### Feature Description

OpenTelemetry has a logger provider interface, so I was wondering if otelfiber can support a LoggerProvider.

Additional Context (optional)

No response

Code Snippet (optional)

Checklist:

• I agree to follow Fiber's Code of Conduct.
• I have checked for existing issues that describe my suggestion prior to opening this one.
• I understand that improperly formatted feature requests may be closed without explanation.</issue_description>

<agent_instructions>- add support for otel pkg logger.

• add unit-tests.
• update documentation with examples.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes 🚀 [Feature]: Add LoggerProvider to otelfiber #1349

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[Copilot]

Pull request overview

Adds OpenTelemetry logging support to the v3/otel Fiber middleware by allowing a configurable LoggerProvider and emitting a correlated log record per request.

Changes:

• Add LoggerProvider to middleware config + WithLoggerProvider(...) option (defaults to global provider when unset).
• Emit one structured log record per request with severity derived from HTTP status and standard HTTP/url attributes.
• Add unit tests for log emission/severity/Next-skip behavior; update docs and module dependencies.

Reviewed changes

Copilot reviewed 6 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
v3/otel/config.go	Adds LoggerProvider field and WithLoggerProvider option.
v3/otel/fiber.go	Initializes OTel logger and emits a per-request log record with severity + attributes.
v3/otel/otel_test/fiber_test.go	Adds in-memory log processor + tests validating emission and severity mapping.
v3/otel/README.md	Documents WithLoggerProvider and adds a usage example.
v3/otel/go.mod	Adds go.opentelemetry.io/otel/log and go.opentelemetry.io/otel/sdk/log deps.
v3/otel/go.sum	Updates sums for new OTel log dependencies.
v3/otel/example/go.mod	Pulls in otel/log as an indirect dependency for the example module.
v3/otel/example/go.sum	Updates sums for the example module’s new indirect dependency.

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[Copilot]

The log record uses the captured ctx variable for logger.Enabled/logger.Emit. Since downstream handlers can mutate the request context via c.SetContext(...), consider using c.Context() here (like the outbound propagator injection does) so emitted logs include any user-added values/baggage and reflect the final active context for the request.

[Copilot]

logRecord.SetTimestamp(start) sets the log timestamp to the beginning of the request even though the record is emitted after the response is processed. This can skew log ordering and make the record appear to occur before the response status is known; consider setting the timestamp to the emit time (and optionally recording the start time/duration as attributes if needed).

Suggested change

	logRecord.SetTimestamp(start)
	logRecord.SetObservedTimestamp(time.Now())
	emitTime := time.Now()
	logRecord.SetTimestamp(emitTime)
	logRecord.SetObservedTimestamp(emitTime)