v0.3.0 — Cleanup & simplification

First release after the cleanup pass. No behavior changes to the
simulation — this is structural and API-surface work.

Highlights

• MIT license (was bespoke source-available "no-execute").
• Single code path. legacy_density salience mode, root-level
  compatibility shims, and the validate_packet() alias are all gone.
• Conventional layout. Runnable entrypoints live under
  examples/. Repo root holds only config, docs, and the package.
• New pyproject.toml — pip install -e ".[dev]" from a clean
  clone Just Works.
• New docs/architecture.md merges the data-flow diagram and
  telemetry schema. README is ~60 lines and leads with what the
  framework does.

Breaking changes

• from temporal_gradient.telemetry.schema import validate_packet →
  use validate_packet_schema.
• ClockRateModulator(salience_mode=..., legacy_density_scale=...) →
  drop both kwargs.
• validate_packet_schema(salience_mode=...) and
  ChronometricVector.from_packet(salience_mode=...) → drop the kwarg.
• clock.tick(input_context=...) → pass psi= directly.
• Legacy "1" schema-version migration → only "1.0" accepted.
• anomaly_detection.run_poc(...) result dict → use
  total_swept_survivors / total_swept_forgotten (the
  memories_alive / memories_forgotten aliases are gone).
• Root-level scripts → now under examples/
  (python examples/anomaly_detection.py,
  python examples/simulation.py, etc.).

Full details and a migration checklist are in CHANGELOG.md.

Tested

166 tests passing on Python 3.10, 3.11, 3.12.