clang-tidy: resolve cppcoreguidelines-owning-memory

[greenc-FNAL]

• Follow C++ Core Guidelines for owning pointers when demangling symbols
• Follow C++ Core Guidelines in test/form/reader.cpp
• Avoid unnecessary (and likely problematic) new() in doRead()
• Clarify and simplify getIndex() while avoiding raw delete
• Qualify linkage as explicity PUBLIC
• Avoid unnecessary (and likely problematic) new() operations
• Use unique_ptr with a custom deleter for clarity and consistency
• Follow C++ Core Guidelines for owning pointers

[Copilot]

Pull request overview

This PR focuses on addressing clang-tidy’s cppcoreguidelines-owning-memory guidance by making ownership intent explicit and reducing raw new/delete usage across FORM ROOT storage, FORM tests, and the Python plugin bindings.

Changes:

• Replaces ad-hoc raw-pointer ownership patterns with clearer ownership annotations (gsl::owner) and RAII (std::unique_ptr) in storage/test code paths.
• Introduces a std::unique_ptr<TTree, Deleter> pattern for ROOT TTree lifetime handling in the write container.
• Wires Microsoft.GSL into the relevant targets (FORM ROOT tests, ROOT storage, and Python plugin) to support gsl::owner usage.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
test/form/test_utils.hpp	Removes an unnecessary new PROD() in doRead() and reads into a raw pointer before wrapping in unique_ptr.
test/form/reader.cpp	Annotates returned pointers as gsl::owner<...*> and links against GSL for ownership annotation support.
test/form/CMakeLists.txt	Links Microsoft.GSL::GSL to the ReadVector test.
plugins/python/src/modulewrap.cpp	Adds gsl::owner annotations for heap-allocated callback/provider functors (but allocations are still leaked).
plugins/python/CMakeLists.txt	Links Microsoft.GSL::GSL into pymodule.
form/storage/storage_reader.cpp	Replaces manual delete of read strings with std::unique_ptr to enforce RAII cleanup in getIndex().
form/storage/CMakeLists.txt	Changes storage link visibility to PUBLIC for core and root_storage.
form/root_storage/root_ttree_write_container.hpp	Switches m_tree to std::unique_ptr<TTree, TTreeDeleter> and documents ownership intent.
form/root_storage/root_ttree_write_container.cpp	Implements TTreeDeleter and uses unique_ptr::reset() for TTree acquisition/creation.
form/root_storage/root_tbranch_read_container.cpp	Avoids explicit allocations before SetBranchAddress() by passing a null pointer-to-pointer buffer.
form/root_storage/demangle_name.cpp	Marks the demangled buffer as gsl::owner<char*> while still freeing with std::free().
form/root_storage/CMakeLists.txt	Links Microsoft.GSL::GSL (PRIVATE) into root_storage.

[codecov]

Codecov Report

❌ Patch coverage is 93.50649% with 5 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
form/root_storage/root_tbranch_read_container.cpp	91.83%	3 Missing and 1 partial ⚠️
form/root_storage/root_ttree_write_container.cpp	83.33%	0 Missing and 1 partial ⚠️

@@            Coverage Diff             @@
##             main     #551      +/-   ##
==========================================
+ Coverage   85.29%   85.39%   +0.09%     
==========================================
  Files         145      145              
  Lines        3679     3710      +31     
  Branches      632      646      +14     
==========================================
+ Hits         3138     3168      +30     
- Misses        324      329       +5     
+ Partials      217      213       -4     

Flag	Coverage Δ
unittests	85.39% <93.50%> (+0.09%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
form/storage/storage_reader.cpp	81.81% <100.00%> (-0.80%)	⬇️
plugins/python/src/modulewrap.cpp	79.97% <100.00%> (-0.24%)	⬇️
form/root_storage/root_ttree_write_container.cpp	58.33% <83.33%> (+8.33%)	⬆️
form/root_storage/root_tbranch_read_container.cpp	91.39% <91.83%> (+12.55%)	⬆️

... and 4 files with indirect coverage changes

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[pcanal]

Looks good to me. If https://github.com/Framework-R-D/phlex/pull/551/changes#r3157633667 is not resolved in this PR, there ought to be an issue open to keep track of its resolution.

[wwuoneway]

LGTM. https://github.com/Framework-R-D/phlex/pull/551/changes#r3157633667 would need a separate issue track.