feat(source): add --fqdn-* flag support to traefik-proxy source

[ivankatliarchuk]

What does it do ?

• traefikSource now accepts a template.Engine (wired from cfg.TemplateEngine) and applies it to all three Traefik CRD types: IngressRoute, IngressRouteTCP, and IngressRouteUDP
• Added endpointsFromTemplate (handles --fqdn-template + --target-template) and endpointsFromFQDNTargetTemplate (handles --fqdn-target-template with host:target pairs), following the identical pattern used by the unstructured source
• Template combination uses the two-step CombineWithEndpoints flow: fqdn-target-template first, then fqdn+target-template — preserving existing rule/annotation-based endpoints when no combine flag is set

Motivation

• The traefik-proxy source did not support DNS name generation via --fqdn-template, preventing users from deriving hostnames from resource metadata (name, namespace, labels) without using annotations
• And added support of --target-template and --fqdn-target-template to make it possible to to override or derive DNS targets from resource metadata

More

• Yes, this PR title follows Conventional Commits
• Yes, I added unit tests
• Yes, I updated end user documentation accordingly

[coveralls]

Coverage Report for CI Build 26903629979

Coverage decreased (-0.05%) to 80.646%

Details

• Coverage decreased (-0.05%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 111 coverage regressions across 1 file.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

111 previously-covered lines in 1 file lost coverage.

File	Lines Losing Coverage	Coverage
traefik_proxy.go	111	67.54%

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Coverage Stats

Relevant Lines:	21536
Covered Lines:	17368
Line Coverage:	80.65%
Coverage Strength:	1444.9 hits per line

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💛 - Coveralls

[mloiseleur]

/lgtm

[ivankatliarchuk]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ivankatliarchuk

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