refactor(config): introduce config module

[paralta]

This PR establishes a new config/ Go module as the single source of truth for all configuration types across the monorepo. Previously, each service (apiserver, reconciler, daemon) owned fragmented config packages — server/config, server/database/config, server/store/oci/config, reconciler/config, and a dozen sub-service config.gofiles — that duplicated type definitions, viper wiring, and defaults. All of those are now deleted and replaced by theconfigmodule plus aconfig/reconciler sub-package for reconciler task types.

[codecov]

Codecov Report

❌ Patch coverage is 70.40816% with 145 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
config/load.go	89.5%	15 Missing and 7 partials ⚠️
config/auth/authn.go	0.0%	13 Missing ⚠️
config/reconciler/name.go	0.0%	12 Missing ⚠️
config/reconciler/regsync.go	0.0%	12 Missing ⚠️
config/reconciler/signature.go	0.0%	12 Missing ⚠️
server/server.go	58.3%	7 Missing and 3 partials ⚠️
config/config.go	66.7%	9 Missing ⚠️
server/authn/service.go	0.0%	8 Missing ⚠️
config/auth/authz.go	0.0%	6 Missing ⚠️
config/database.go	57.1%	3 Missing and 3 partials ⚠️
... and 14 more

📢 Thoughts on this report? Let us know!

[paralta]

These changes will not be included in https://github.com/agntcy/dir/milestone/14, thus keeping this PR as draft.