[PyFDB] fdb-717: Improvements local dev setup pyfdb

[tbkr]

Description

Needed for local dev setup. No need to adjust the PYTHONPATH anymore. Installing the staging directories in build is sufficient now (after setting findlibs up for the local dev ofc).

Contributor Declaration

By opening this pull request, I affirm the following:

• All authors agree to the Contributor License Agreement.
• The code follows the project's coding standards.
• I have performed self-review and added comments where needed.
• I have added or updated tests to verify that my changes are effective and functional.
• I have run all existing tests and confirmed they pass.

🌈🌦️📖🚧 Documentation FDB 🚧📖🌦️🌈
https://sites.ecmwf.int/docs/fdb/pull-requests/PR-322

[Copilot]

Pull request overview

This PR improves the local development workflow for PyFDB by making the CMake staging area directly installable/importable (reducing the need for manual PYTHONPATH manipulation) and by documenting the expected setup and common failure modes.

Changes:

• Make pyfdb_bindings behave as a proper Python package in the staging area by copying an __init__.py alongside the built extension.
• Add pytest configuration (--import-mode=importlib) and empty test-package __init__.py files to prevent import-name clashes during test collection.
• Add/refresh PyFDB documentation: a detailed dev setup guide, staging area internals, and an FAQ; turn the old development page into a redirect.

Reviewed changes

Copilot reviewed 8 out of 11 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
src/pyfdb_bindings/CMakeLists.txt	Copies __init__.py into the built extension output directory to make the staged bindings importable as a package.
src/pyfdb_bindings/__init__.py	New package initializer intended to import the compiled extension with a clearer error on failure.
pyproject.toml	Adds pytest import-mode configuration to avoid test/module name collisions.
tests/pyfdb/__init__.py	Marks the tests/pyfdb directory as a Python package (empty file).
tests/z3fdb/__init__.py	Marks the tests/z3fdb directory as a Python package (empty file).
tests/pychunked_data_view/__init__.py	Marks the tests/pychunked_data_view directory as a Python package (empty file).
docs/pyfdb/index.rst	Updates navigation to include the new FAQ and adds a “Technical Insights” section.
docs/pyfdb/technical_insights.rst	Adds a comprehensive local development setup guide for a full stack build + editable install.
docs/pyfdb/staging_area.rst	Documents the staging directory layout and what gets generated/copied there.
docs/pyfdb/faq.rst	Adds troubleshooting guidance for common import and runtime failures.
docs/pyfdb/development.rst	Replaces the old content with a note pointing to the new dev setup guide.

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.51%. Comparing base (a29adbb) to head (02c4e40).
⚠️ Report is 2 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #322      +/-   ##
===========================================
+ Coverage    77.36%   77.51%   +0.14%     
===========================================
  Files          410      411       +1     
  Lines        27483    27553      +70     
  Branches      2756     2769      +13     
===========================================
+ Hits         21263    21358      +95     
+ Misses        6220     6195      -25     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[jharwood0]

pyfdb_bindings package changes makes sense 😃

few minor comments / questions but no major blockers