Refactor PSD extraction: simplify to latest-only + add R2 support

## Key Changes

1. **Simplified extraction logic**
   - Changed from downloading 220+ historical archives to checking only latest available month
   - Tries current month and falls back up to 3 months (handles USDA publication lag)
   - Architecture advisor insight: ETags naturally deduplicate, historical year/month structure was unnecessary

2. **Flat storage structure**
   - Old: `data/{year}/{month}/{etag}.zip`
   - New: `data/{etag}.zip` (local) or `psd/{etag}.zip` (R2)
   - Migrated 226 existing files to flat structure

3. **Dual storage modes**
   - **Local mode**: Downloads to local directory (development)
   - **R2 mode**: Uploads to Cloudflare R2 (production)
   - Mode determined by presence of R2 environment variables
   - Added boto3 dependency for S3-compatible R2 API

4. **Updated raw SQLMesh model**
   - Changed pattern from `**/*.zip` to `*.zip` to match flat structure

## Benefits

- Simpler: Single file check instead of 220+ URL attempts
- Efficient: ETag-based deduplication works naturally
- Flexible: Supports both local dev and production R2 storage
- Maintainable: Removed unnecessary complexity

## Testing

- ✅ Local extraction works and respects ETags
- ✅ Falls back correctly when current month unavailable
- ✅ Linting passes

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

uv.lock

@@ -147,6 +147,34 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/27/44/d2ef5e87509158ad2187f4dd0852df80695bb1ee0cfe0a684727b01a69e0/bcrypt-5.0.0-cp39-abi3-win_arm64.whl", hash = "sha256:f2347d3534e76bf50bca5500989d6c1d05ed64b440408057a37673282c654927", size = 144953, upload-time = "2025-09-25T19:50:37.32Z" },
 ]
 
+[[package]]
+name = "boto3"
+version = "1.40.55"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "botocore" },
+    { name = "jmespath" },
+    { name = "s3transfer" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/50/d8/a279c054e0c9731172f05b3d118f3ffc9d74806657f84fc0c93c42d1bb5d/boto3-1.40.55.tar.gz", hash = "sha256:27e35b4fa9edd414ce06c1a748bf57cacd8203271847d93fc1053e4a4ec6e1a9", size = 111590, upload-time = "2025-10-17T19:34:56.753Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/42/8c/559c6145d857ed953536a83f3a94915bbd5d3d2d406db1abf8bf40be7645/boto3-1.40.55-py3-none-any.whl", hash = "sha256:2e30f5a0d49e107b8a5c0c487891afd300bfa410e1d918bf187ae45ac3839332", size = 139322, upload-time = "2025-10-17T19:34:55.028Z" },
+]
+
+[[package]]
+name = "botocore"
+version = "1.40.55"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "jmespath" },
+    { name = "python-dateutil" },
+    { name = "urllib3" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/a4/92/dce4842b2e215d213d34b064fcdd13c6a782c43344e77336bcde586e9229/botocore-1.40.55.tar.gz", hash = "sha256:79b6472e2de92b3519d44fc1eec8c5feced7f99a0d10fdea6dc93133426057c1", size = 14446917, upload-time = "2025-10-17T19:34:47.44Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/21/30/f13bbc36e83b78777ff1abf50a084efcc3336b808e76560d8c5a0c9219e0/botocore-1.40.55-py3-none-any.whl", hash = "sha256:cdc38f7a4ddb30a2cd1cdd4fabde2a5a16e41b5a642292e1c30de5c4e46f5d44", size = 14116107, upload-time = "2025-10-17T19:34:44.398Z" },
+]
+
 [[package]]
 name = "cattrs"
 version = "25.1.1"
@@ -765,6 +793,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/62/a1/3d680cbfd5f4b8f15abc1d571870c5fc3e594bb582bc3b64ea099db13e56/jinja2-3.1.6-py3-none-any.whl", hash = "sha256:85ece4451f492d0c13c5dd7c13a64681a86afae63a5f347908daf103ce6d2f67", size = 134899, upload-time = "2025-03-05T20:05:00.369Z" },
 ]
 
+[[package]]
+name = "jmespath"
+version = "1.0.1"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/00/2a/e867e8531cf3e36b41201936b7fa7ba7b5702dbef42922193f05c8976cd6/jmespath-1.0.1.tar.gz", hash = "sha256:90261b206d6defd58fdd5e85f478bf633a2901798906be2ad389150c5c60edbe", size = 25843, upload-time = "2022-06-17T18:00:12.224Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/31/b4/b9b800c45527aadd64d5b442f9b932b00648617eb5d63d2c7a6587b7cafc/jmespath-1.0.1-py3-none-any.whl", hash = "sha256:02e2e4cc71b5bcab88332eebf907519190dd9e6e82107fa7f83b1003a6252980", size = 20256, upload-time = "2022-06-17T18:00:10.251Z" },
+]
+
 [[package]]
 name = "json-stream"
 version = "2.3.3"
@@ -1225,12 +1262,14 @@ name = "psdonline"
 version = "0.1.0"
 source = { editable = "extract/psdonline" }
 dependencies = [
+    { name = "boto3" },
     { name = "niquests" },
     { name = "pendulum" },
 ]
 
 [package.metadata]
 requires-dist = [
+    { name = "boto3", specifier = ">=1.40.55" },
     { name = "niquests", specifier = ">=3.14.1" },
     { name = "pendulum", specifier = ">=3.1.0" },
 ]
@@ -1740,6 +1779,18 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/24/3c/21cf283d67af33a8e6ed242396863af195a8a6134ec581524fd22b9811b6/ruff-0.12.10-py3-none-win_arm64.whl", hash = "sha256:cc138cc06ed9d4bfa9d667a65af7172b47840e1a98b02ce7011c391e54635ffc", size = 12074225, upload-time = "2025-08-21T18:23:20.137Z" },
 ]
 
+[[package]]
+name = "s3transfer"
+version = "0.14.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "botocore" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/62/74/8d69dcb7a9efe8baa2046891735e5dfe433ad558ae23d9e3c14c633d1d58/s3transfer-0.14.0.tar.gz", hash = "sha256:eff12264e7c8b4985074ccce27a3b38a485bb7f7422cc8046fee9be4983e4125", size = 151547, upload-time = "2025-09-09T19:23:31.089Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/48/f0/ae7ca09223a81a1d890b2557186ea015f6e0502e9b8cb8e1813f1d8cfa4e/s3transfer-0.14.0-py3-none-any.whl", hash = "sha256:ea3b790c7077558ed1f02a3072fb3cb992bbbd253392f4b6e9e8976941c7d456", size = 85712, upload-time = "2025-09-09T19:23:30.041Z" },
+]
+
 [[package]]
 name = "semver"
 version = "3.0.4"