docs: publish Tend Compose continuity evidence

Export the reviewed allowlisted snapshot from private source commit 07c1655921f21ee5e4fc4d85639d199e8867b17d. This records the Docker Compose activation, schema-compatible rollback, and stateful migration resource findings from Observatory Preview 19 dogfooding.

AI-Assisted: OpenAI Codex
Signed-off-by: Cole Speelman <crspeelman@gmail.com>

examples/server/slots/example-site-blue.env

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: 0BSD
+EXAMPLE_LISTEN=127.0.0.1:8090

examples/server/slots/example-site-green.env

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+# SPDX-License-Identifier: 0BSD
+EXAMPLE_LISTEN=127.0.0.1:8091