Callbacks service docs updated

ci/dev/callbacks.dockerfile

@@ -26,8 +26,8 @@ WORKDIR /src
 COPY --from=builder /src/api/proto ./api/proto
 COPY --from=builder /src/api/pkg ./api/pkg
 
-# Copy vault-aware entrypoint wrapper
-COPY api/edge/callbacks/entrypoint.sh /app/entrypoint.sh
+# Copy dev-specific entrypoint script
+COPY ci/dev/entrypoints/callbacks.sh /app/entrypoint.sh
 RUN chmod +x /app/entrypoint.sh
 
 # Source code will be mounted at runtime

ci/dev/entrypoints/callbacks.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -eu
+
+# Load Vault token from file if VAULT_TOKEN_FILE is set
+if [ -n "${VAULT_TOKEN_FILE:-}" ] && [ -f "${VAULT_TOKEN_FILE}" ]; then
+  token="$(cat "${VAULT_TOKEN_FILE}" 2>/dev/null | tr -d '[:space:]')"
+  if [ -n "${token}" ]; then
+    export VAULT_TOKEN="${token}"
+  fi
+fi
+
+if [ -z "${VAULT_TOKEN:-}" ]; then
+  echo "[entrypoint] VAULT_TOKEN is not set; expected Vault Agent sink to write a token to ${VAULT_TOKEN_FILE:-/run/vault/token}" >&2
+fi
+
+# Execute the command passed as arguments (e.g., air)
+exec "$@"