refactor: harden SDK error taxonomy, fix Python Makefile, add project…

[JeanExtreme002]

Why is this PR necessary, what does it do?

This PR bundles two related changes to align and harden both SDKs (Python and Node.js).

1. Rename packages to FlightRadarAPI

Aligns the Python internal package name with the PyPI distribution and with the npm package flightradarapi, so both SDKs share the same identifier.

• Python: FlightRadar24 → FlightRadarAPI. A deprecation shim keeps from FlightRadar24 import ... working for one more release (re-exports the new package
  and aliases every submodule via sys.modules, emitting a DeprecationWarning).
• Node.js: only the directory was renamed (nodejs/FlightRadar24 → nodejs/FlightRadarAPI). Since users import via the npm name flightradarapi, the change
  is invisible to consumers.

2. Harden error taxonomy, Python Makefile, and project docs (bump to 1.5.1)

Node SDK:

• Replace generic Error throws with TypeError/RangeError in api.js, entities/entity.js, and flightTrackerConfig.js, matching the taxonomy already
  used by the Python SDK. Specific instanceof checks now work correctly.
• Add APIClient.requestStandalone() — a stateless request path that reuses the TLS dispatcher but bypasses the shared cookie jar (mirrors request_standalone
  in the Python SDK). getAirports and getFlightDetails now use it, so concurrent fan-out can't race writes onto session cookies.
• Method exported in index.d.ts.

Cross-SDK code clarity:

• Name the magic bearings in get_bounds_by_point (bearing_sw / bearing_ne) with short comments explaining the haversine corner derivation. Python and Node
  updated in lockstep.

Python packaging:

• Force-include py.typed in the wheel via [tool.hatch.build.targets.wheel.force-include], guaranteeing the PEP 561 marker regardless of the global exclude
  list.

Python Makefile (substantial revision):

• Auto-detects venv/ — make test/lint/etc. work without activating the venv first.
• Fixes make dev-setup, which previously installed deps into the system interpreter instead of the freshly created venv.
• Centralises dev tooling in DEV_TOOLS; adds pip-audit, removes deprecated safety.
• Centralises COVERAGE_MIN = 60.
• Splits clean-build (build artefacts) from clean — build/validate/publish no longer wipe coverage/test caches.
• all now depends on install-dev.
• Replaces broken Sphinx docs target with mkdocs build; adds docs-serve.
• update-deps also upgrades dev tools.
• venv target uses literal python3 to avoid the venv recreating itself through its own interpreter.
• Removes dead code (install-deps, venv-activate, unused colour vars).

Project documentation:

• Adds SECURITY.md (disclosure process, scope, supported-version policy).
• Adds CONTRIBUTING.md (dev setup for both SDKs, the four test tiers, public surface that must stay aligned between Python and Node, style, release/versioning
  rules).
• Links both from the top-level README.md.

Checklist (complete all items):

• Added tests as necessary.
• There is no breaking change for existing features.

References:

No references to be shared.

Notes:

The Python package rename is the only user-visible change, and it is backwards compatible via the FlightRadar24 deprecation shim (covered by
python/tests/test_legacy_import.py). Suggested migration path for consumers: switch imports to FlightRadarAPI before the shim is removed in a future
release