Add S3 publishing and Databricks landing flow (#6)

* Add S3 publishing and Databricks landing templates

* Tighten missing S3 manifest detection

* Handle empty Databricks source map manifests

* Respect zero max iterations in run service

* Write manifest before deleting stale current objects

* Scrub environment-specific example tfvars

* Exit bounded runs immediately after final iteration

* Retry failed S3 publishes on no-op iterations

Author: anandpant

.vscode/extensions.json

@@ -0,0 +1,6 @@
+{
+    "recommendations": [
+        "hashicorp.terraform",
+        "rust-lang.rust-analyzer"
+    ]
+}