chore(release): 6.2.6 - fix cloud storage read-after-write consistency

Fix add() → relate() race condition in cloud storage (GCS, S3, R2, Azure)

Problem:
- In high-volume mode, writes go to buffer instead of direct storage
- Cache was NOT populated when buffering
- add() returns but relate() fails with "Source entity not found"

Solution:
- Populate cache BEFORE adding to write buffer
- Ensures immediate read-after-write consistency
- Buffer still flushes asynchronously for performance

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

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

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@soulcraft/brainy",
-  "version": "6.2.5",
+  "version": "6.2.6",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@soulcraft/brainy",
-      "version": "6.2.5",
+      "version": "6.2.6",
       "license": "MIT",
       "dependencies": {
         "@aws-sdk/client-s3": "^3.540.0",