feat(jaeger): Expose default component factories via jaegercli.Components

[iammdzaidalam]

Which problem is this PR solving?

• Resolves Expose default component factories publicly as a companion to jaegercli.NewCommand #9064. jaegercli.NewCommand takes factories as a parameter, but there was no public way to obtain Jaeger's default set, so an out-of-tree distribution that wants the stock components plus one extra extension has to hand-copy the whole list out of cmd/jaeger/internal and keep it in sync.

Description of the changes

• Adds jaegercli.Components(), a re-export of internal.Components(), documented with the add-an-extension usage snippet
• cmd/jaeger/main.go now calls it, so the default binary doubles as the reference example and no longer imports cmd/jaeger/internal
• The exported set is the stock binary's set as is, so a distribution starting from it gets exactly what cmd/jaeger ships, including the e2e-only storagecleaner and remotestorage

How was this change tested?

• New components_test.go covers parity with internal.Components(), the expected factories being present, and that removing one does not affect a later call
• Both assertions were checked against a deliberately broken Components() so they fail when they should

Checklist

• I have read https://github.com/jaegertracing/jaeger/blob/main/CONTRIBUTING_GUIDELINES.md
• I have signed all commits
• I have added unit tests for the new functionality
• I have run lint and test steps successfully: make lint test

AI Usage in this PR

• Light: AI provided minor assistance (formatting, simple suggestions)

[Copilot]

Pull request overview

This PR adds a public way for downstream/custom Jaeger distributions to reuse the stock Jaeger component factory set (previously only available via cmd/jaeger/internal), enabling “default + extensions” without copying Jaeger’s internal component list.

Changes:

• Added jaegercli.Components() as a thin, documented re-export of internal.Components().
• Updated the standard cmd/jaeger binary to use jaegercli.Components() (so it serves as the reference example and avoids importing cmd/jaeger/internal directly).
• Added unit tests to ensure the exported factories match internal.Components() and that repeated calls return independent factory sets.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
cmd/jaeger/main.go	Switches the binary to use the new public jaegercli.Components() entrypoint.
cmd/jaeger/jaegercli/components.go	Introduces the exported Components() API and documents intended downstream usage.
cmd/jaeger/jaegercli/components_test.go	Adds tests for parity with internal defaults and independence across calls.