GDAL MCP

# ADR-0013-configuration-isolation.md ## Title Per-request GDAL configuration isolation ## Status Proposed ## Context GDAL has global config/state that can bleed across operations. ## Decision * Wrap each tool in `rasterio.Env(...)` (and/or GDAL config contexts) to set per-request options (`GDAL_CACHEMAX`, VSI auth, threads). * Avoid global mutation; never rely on ambient environment. ## Consequences * Pro: Deterministic behavior, safer multi-tenant ops. * Con: Must plumb config options through tool params.