fix(config_overrides): make config_overrides public, fix clippy & doc checks

* deps: add uuid crate 1.23

* fix: add missing traits; macros and types pub.

* fix: adapt pathes

* fix: make builder pub

* fix: make role-utils and role-group-utils pub

* fix: correct fragment and merge macro path

* fix: remaining precommit

* fix: doc tests

* feat(v2): add shared config-file writers (java-properties/Hadoop-XML + Flask)

Adds v2::config_file_writer (to_java_properties_string + to_hadoop_xml, backed
by the java-properties and xml crates) and v2::flask_config_writer (the Flask
App Builder Python config writer), both originally from the product-config
crate's writer modules and until now vendored separately into the operators
(hdfs/hbase/hive byte-identical full copies; kafka/nifi/zookeeper java-only
subsets; airflow/superset identical Flask copies). Unit tests moved along with
the code; minor lint-driven cleanups only (use_self, format_push_string,
identical match arms, no unwrap in Result-returning tests) — rendered output is
unchanged and pinned by the tests.

Operators will migrate to these in follow-up commits, deleting their vendored
copies.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs: fix rustdoc warnings (broken intra-doc links, bare URLs)

stackable-operator: intra-doc links within the crate must use `crate::`
rather than the package name `stackable_operator::`, which is not in
scope and produced `broken_intra_doc_links` warnings. Also wrap two bare
URLs in the scaler docs in angle brackets so rustdoc renders them as
hyperlinks.

stackable-telemetry: `SettingsBuilder` is not imported in
`tracing/mod.rs` (only `Settings` is), so the four doc links to it did
not resolve. Point them at `settings::SettingsBuilder` via the child
module, keeping the rendered link text unchanged.

`cargo doc --document-private-items` is now warning-free across the
workspace.

* Update crates/stackable-operator/src/v2/config_file_writer.rs

Co-authored-by: maltesander <malte.sander.it@gmail.com>

* Apply suggestions from code review

Co-authored-by: maltesander <malte.sander.it@gmail.com>

* remove error suffix and clippy

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
Co-authored-by: maltesander <malte.sander.it@gmail.com>

* fix: remove option part for properties writer (now takes <String,String> instead of <String,<Option<String>>

* fix: precommit

)

* Relax the length constraints of cluster, role and role group name

* Adapt compile-time assertions

* Check that ensure_max_length is only called with ASCII resource names

refactor: make replicas optional for HPA support