[fern-replay] Initialize Replay for SDK customizations (#833)

## Replay Initialization

This PR initializes [Fern Replay](https://buildwithfern.com) for this
SDK repository.
Replay automatically preserves your customizations across SDK
regenerations.

**Base generation commit:** `ae22120`

Clean start — no historical patches imported. Future customizations will
be tracked automatically.

---
Once merged, your customizations will be automatically preserved on
future `fern generate` runs.

Co-authored-by: fern-api[bot] <115122769+fern-api[bot]@users.noreply.github.com>

Author: fern-api[bot]

.fern/replay.lock

@@ -0,0 +1,10 @@
+# DO NOT EDIT MANUALLY - Managed by Fern Replay
+version: "1.0"
+generations:
+  - commit_sha: de316f0260ef1fa7c3626cbe771b167fd119439c
+    tree_hash: 8a8087896ee9fee5f1d6bb4c86a8f007a0a4f12f
+    timestamp: 2026-04-28T17:41:46.911Z
+    cli_version: unknown
+    generator_versions: {}
+current_generation: de316f0260ef1fa7c3626cbe771b167fd119439c
+patches: []

.fernignore

@@ -41,3 +41,6 @@ LICENSE
 
 # GitHub workflows and configuration
 .github/
+.fern/replay.lock
+.fern/replay.yml
+.gitattributes