test(ci): stabilize CI harness, debloat test suites, and modernize tooling

[cofin]

Summary

Stabilize CI infrastructure, pytest harness, Makefile targets, and consolidate test suite assertions and parametrization.

Changes

• Tooling & Makefile:

  • Pruned 7 obsolete infra-* targets from Makefile; consolidated make check-all to run lint coverage once without duplicate test runs.
  • Replaced custom AST pre-commit hook (no_future_annotations.py) and PyPI README generator with native Ruff TID251 rule; deleted docs/PYPI_README.md.
  • Bounded CI watchdog to runner process group (pytest_pgid) with exit trap and signal escalation (SIGABRT -> SIGTERM -> SIGKILL).

• Documentation & Examples:

  • Relocated migration CLI workflow scenarios from docs/examples/quickstart_migrations.py to tests/integration/cli/test_migration_quickstart.py.
  • Replaced tools/build_docs.py with direct make docs in .github/workflows/docs.yml.
  • Pruned 7 unused Sphinx extensions and dependencies (jupyter_sphinx, nbsphinx, sphinx_datatables, sphinx_tabs, sphinx_togglebutton, sphinx.ext.todo, tools.sphinx_ext.changelog).
  • Removed redundant .gitkeep placeholders and unused theme.js.

• Test Fixtures & Concurrency:

  • Isolated mutable extension_config per test in tests/integration/adapters/postgres/psqlpy/extensions/adk/test_owner_id_column.py.
  • Updated compiled detection in tests/conftest.py using importlib.machinery.EXTENSION_SUFFIXES for .so and .pyd.
  • Implemented interruptible synchronous event listener thread shutdown with bounded polling.
  • Verified BigQuery finite timeout configuration and offline Oracle mock separation.

• Test Suite Consolidation & Parametrization:

  • Eliminated 9 meta-test and AST source scanner files (test_sqlglot_arg_contracts.py, test_mypyc_boundary.py, test_makefile_quality.py, test_conf.py, etc.).
  • Replaced tautological checks (assert stmt.parameters or True) with exact assertions; cleaned structural not hasattr assertions.
  • Consolidated 128 type guard functions to 62 parametrized tables and 97 value conversion functions to 32 parametrized tables with 100% variant coverage preserved.

Verification

• make lint: clean exit 0 (Prek, Ruff check/format, Mypy, Pyright, slotscheck, Zizmor).
• make docs: clean exit 0.
• Unit tests: 898 passed, 1 skipped.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 81.81818% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.90%. Comparing base (9c69704) to head (ddbb2a8).

Files with missing lines	Patch %	Lines
sqlspec/extensions/events/_queue.py	71.42%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #783      +/-   ##
==========================================
- Coverage   78.91%   78.90%   -0.01%     
==========================================
  Files         491      491              
  Lines       72437    72443       +6     
  Branches    10181    10184       +3     
==========================================
- Hits        57163    57162       -1     
- Misses      11767    11772       +5     
- Partials     3507     3509       +2     

Flag	Coverage Δ
integration	62.38% <27.27%> (-0.01%)	⬇️
py3.10	77.04% <27.27%> (-0.02%)	⬇️
py3.11	77.05% <27.27%> (-0.02%)	⬇️
py3.12	77.05% <27.27%> (-0.01%)	⬇️
py3.13	77.04% <27.27%> (-0.03%)	⬇️
py3.14	78.17% <81.81%> (-0.02%)	⬇️
unit	67.26% <81.81%> (+0.05%)	⬆️

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

Files with missing lines	Coverage Δ
sqlspec/extensions/events/_channel.py	80.74% <100.00%> (+0.08%)	⬆️
sqlspec/extensions/events/_queue.py	86.11% <71.42%> (+0.13%)	⬆️

... and 3 files with indirect coverage changes

🚀 New features to boost your workflow:

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