Support duplicate handling for Appwrite imports

[premtsd-code]

Summary

• add Appwrite duplicate handling modes for skip and overwrite across imported resources
• carry createdAt and updatedAt through Appwrite source resources so overwrite only updates when the source is newer
• preserve fail-mode create behavior as the default path
• overwrite SDK-backed resources in place where supported, match natural-key resources such as memberships/platforms/rules, and replace existing files by deleting only the matching destination file ID before re-upload
• keep deployment overwrite conservative: existing function/site deployments are skipped instead of deleted and recreated

Validation

• composer format
• composer lint
• composer check
• live source-to-destination fail-mode migration
• live skip-mode migration with source-only resources and existing destination conflicts
• live overwrite-mode migration with matching resources, source-only resources, and destination-only sentinels
• live file overwrite check confirmed matching file content is replaced, source-only file is created, and unrelated destination file is preserved

Review Notes

• overwrite only applies when the source updatedAt is newer than destination updatedAt; otherwise the resource is skipped
• file overwrite deletes only the matching file ID in the matching bucket, then reuses the existing upload path
• deployment overwrite remains skipped because safely replacing deployment artifacts needs a separate delete-and-reupload recovery path

[greptile-apps]

Greptile Summary

This PR adds skip and overwrite duplicate-handling modes to the Appwrite-to-Appwrite migration path. It propagates createdAt/updatedAt timestamps through all resource models so that overwrite can be gated on "source is newer than destination," and adds per-resource SDK or DB lookups before each create operation.

• Duplicate handling: a new handleDuplicate helper centralises the skip/overwrite/create routing; every resource type (buckets, files, users, teams, memberships, functions, env vars, deployments, sites, messaging providers/topics/subscribers/messages, webhooks, platforms, API keys, and proxy rules) now has a corresponding natural-key lookup and conditional update or skip path.
• Source timestamp propagation: createdAt/updatedAt are wired through all 11 resource model constructors and carried from the Appwrite source API responses; the Range header capitalisation and the last-chunk content-range end-byte are also fixed as part of the same pass.
• Chunked upload continuity: a skippedChunkedUploads map guards subsequent chunks of a skipped file or deployment from attempting a partial upload, and a probe request is added to determine deployment size when the server omits a content-length header.

Confidence Score: 4/5

The logic for skip and overwrite is sound across most resource types; existing open threads on the file/deployment delete-then-upload window and the file overwrite timestamp check are the main remaining concerns before merging.

The duplicate-handling plumbing is well-structured and the live-migration validation described in the PR gives reasonable confidence. Two open issues from the previous review round have not been closed: file overwrite always replaces regardless of whether the source is actually newer, and the delete-before-upload window leaves a destination file absent if the upload fails mid-stream.

src/Migration/Destinations/Appwrite.php: the importFile overwrite path and importDeploymentWithDuplicateCheck both warrant a second look before merge.

Important Files Changed

Filename	Overview
src/Migration/Destinations/Appwrite.php	Core of the PR: adds handleDuplicate/getSdkResourceOrNull helpers plus per-resource skip/overwrite logic. Several pre-existing issues remain open in review threads (non-atomic file delete, file overwrite skipping timestamp check); the new provider/topic/subscriber/message duplicate handling is logically correct with timestamps already populated from source.
src/Migration/Sources/Appwrite.php	Adds createdAt/updatedAt propagation for all migrated resource types; fixes lowercase 'range' to 'Range' header; introduces firstChunkData probe for deployments missing content-length. The probe's open-ended range could over-fetch for large deployments.
src/Migration/Resources/Auth/User.php	Adds optional createdAt/updatedAt constructor params and round-trips them through fromArray/jsonSerialize; no logic changes.
src/Migration/Resources/Functions/Deployment.php	Adds optional createdAt/updatedAt constructor params; no logic changes.
src/Migration/Resources/Storage/File.php	Adds optional createdAt/updatedAt constructor params; no logic changes.

_{Reviews (11): Last reviewed commit: "Respect timestamps for binary overwrites" | Re-trigger Greptile}