Complete rewrite of docs/pinescript.md to include every .pine file
organized by category (core, FIR trends, IIR trends, filters,
oscillators, dynamics, momentum, volatility, volume, channels,
cycles, reversals, forecasts, statistics, numerics, errors).
Previously listed ~120 indicators with many missing categories.
- Add docs/license.md with Apache 2.0 rationale and patent protection analysis
- Add docs/python.md and docs/pinescript.md platform guides
- Expand README license section with disclosure and link to rationale
- Update docs/api.md and docs/architecture.md
- Update Python bindings: helpers, all indicator modules, pyproject.toml
- Add Python tests for Arrow and Polars integration
- Update TValue core type and documentation
- Add fix_length_to_period tooling script