Sync CLAUDE.md with main-3.0-dev (#1172)

Add CLAUDE.md  (#1168)

* add claude md

* change nox examples python version to 3.12

Author: asonnenschein

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Development Commands
+
+### Testing
+- **Run all tests**: `nox` (runs lint, analyze, test, coverage, docs)
+- **Run tests only**: `nox -s test`
+- **Run tests on specific Python version**: `nox -s test-3.12`
+- **Run single test file**: `nox -s test-3.12 -- tests/unit/test_http.py`
+- **Run tests by keyword**: `nox -s test-3.12 -- -k test__Limiter`
+- **Fast rerun (reuse environments)**: `nox -r`
+
+### Linting and Code Quality
+- **Linting**: `nox -s lint`
+- **Type checking**: `nox -s analyze`
+- **Code coverage**: `nox -s coverage`
+- **Format code**: `yapf --in-place -r .`
+- **Check formatting**: `yapf --diff -r .`
+
+### Documentation
+- **Build docs**: `nox -s docs`
+- **Serve docs locally**: `nox -s watch`
+- **Test documentation examples**: `nox -s docs_test`
+
+### Example Testing
+- **Test all examples**: `nox -s examples`
+- **Test specific example**: `nox -s examples -- script_name.py`
+
+### Building and Publishing
+- **Build package**: `nox -s build`
+- **Clean build directories**: `nox -s clean`
+
+## Code Architecture
+
+### High-Level Structure
+The Planet SDK provides both a Python API and CLI for Planet's APIs (Data, Orders, Subscriptions, Features).
+
+### Core Components
+
+**API Clients** (`planet/clients/`):
+- `DataClient` - Search Planet's imagery catalog
+- `OrdersClient` - Process and download imagery
+- `SubscriptionsClient` - Auto-process and deliver imagery
+- `FeaturesClient` - Upload areas of interest
+
+**Sync Client** (`planet/sync/`):
+- `Planet` class - High-level synchronous interface combining all clients
+
+**CLI** (`planet/cli/`):
+- Entry point: `planet.cli.cli:main`
+- Command modules: `data.py`, `orders.py`, `subscriptions.py`, `features.py`
+
+**Core Infrastructure**:
+- `http.py` - HTTP session management and authentication
+- `auth.py` - Authentication handling
+- `models.py` - Data models and response objects
+- `exceptions.py` - Custom exception classes
+
+**Request Building**:
+- `data_filter.py` - Data API search filters
+- `order_request.py` - Orders API request construction
+- `subscription_request.py` - Subscriptions API request construction
+
+### Key Patterns
+- All API clients extend `base.py:BaseClient`
+- Async and sync versions available (clients vs sync modules)
+- CLI commands use Click framework with shared options in `options.py`
+- Request/response validation via `specs.py` and `models.py`
+
+## Testing Configuration
+- Uses pytest with configuration in `setup.cfg`
+- Supports Python 3.9-3.13
+- Coverage threshold: 90% (configured in setup.cfg)
+- Integration tests require Planet API credentials
+- Unit tests in `tests/unit/`, integration tests in `tests/integration/`
+
+## Code Style
+- Follows PEP8 via YAPF formatter
+- Type hints checked with mypy
+- Flake8 linting with specific ignores (see setup.cfg)
+- Docstrings in Google format for auto-generated API docs