Merge Sentry error tracking (#116)

Merge A3: R2 LiDAR tile cache (#112)

feat(app): Sentry error tracking, env-gated + secret-scrubbed (obs MVP)

feat(app): async batch via Cloud Tasks, serverless-safe (B3)

feat(app): optional Cloudflare R2 LiDAR tile cache (A3)

feat(app): Clerk auth — session verification + sign-in UI + invite-only provisioning (#103)

feat(app): P1d — Postgres (Neon) backend behind a dialect-aware Database

feat(parcels): statewide GeoPackage fallback source (PARCELS_FALLBACK, off by default)

chore(deploy): pre-bake the cascade EoMT model into the Docker image; findings corrections

build: pin the dependency tree and model revisions (reproducible deploys)

build: pre-bake SAM (sam-vit-base) into the image for SAM_RESTRICT

fix(docker): install torchvision — required by transformers' Mask2Former processor

refactor: replace PDAL with laspy + pyproj — pure-wheel dependency stack

fix(docker): conda env 'app' instead of pinning python in base

refactor: restructure into src/lawn_estimator package

feat: hardened API with batch jobs, partner web page, deployable Dockerfile

checkpoint: NAIP imagery, multi-tile LiDAR, FastAPI wrapper (pre-refactor baseline)