Summary

Implements SCRUM-9 request correlation as an opt-in runtime feature without changing database persistence.

• Adds correlation helpers for safe request IDs, W3C traceparent trace IDs, route metadata, low-cardinality labels, and allowlisted opaque context IDs.
• Adds a ContextVar-backed logging context for request-scoped application logging.
• Wires middleware request attributes and signal payload keys: correlation and low_cardinality.
• Updates README, Sphinx docs, tutorials, compliance/operations guidance, and llms.txt.
• Adds tests for helper behavior, middleware integration, unchanged DB payload shape, no model fields, and no migration additions.

Database Boundary

This PR intentionally does not add APILogsModel fields, migrations, admin columns, database indexes, or synthetic queued database payload fields. Correlation is exposed through request attributes, logging context, and signals only.

Validation

• python -m django test tests --settings=tests.test_settings --verbosity=1 -> 180 tests OK
• python test_runner_simple.py -> 25 tests OK
• python -m django makemigrations drf_api_logger --settings=tests.test_settings --check --dry-run --verbosity=2 -> No changes detected
• python -m sphinx -b html docs (Join-Path $env:TEMP 'drf-api-logger-docs-build-pr') -W --keep-going -> build succeeded
• git diff --check HEAD -> clean

Notes

origin/main already includes SCRUM-8 via PR #125, so this branch was rebased onto current origin/main before push.