Add v154 wasmvm library compatibility documentation (#3199)

Author: masih

sei-wasmd/x/wasm/artifacts/v154/api/README.md

@@ -0,0 +1,38 @@
+# Cosmovisor and `libwasmvm154` During the v6.4 Upgrade Window
+
+## Summary
+
+During the transition from **v6.3.x** to **v6.4.0**, nodes running under `cosmovisor` may still execute the **v6.3.x** binary until the upgrade height is reached. That binary depends on the legacy shared library:
+
+- `libwasmvm154.x86_64.so`
+
+To keep the currently active binary working while **v6.4.0** is staged, the required wasm shared libraries must remain available in the runtime library path during the upgrade window.
+
+For **v6.4**, the fix is to **place the required shared libraries in the expected runtime location** so the active pre-upgrade binary can continue to start normally.
+
+For **v6.5**, the legacy `v154` dependency is no longer needed and can be removed.
+
+---
+
+## Why this happens
+
+`cosmovisor` is expected to keep the **old binary active** until the chain reaches the configured upgrade height.
+
+That means the following is normal before the upgrade executes:
+
+- `current` still points to the **v6.3.x** binary
+- the **v6.4.0** binary may already be staged on disk
+- both versions may need to coexist temporarily
+
+The issue is that the active **v6.3.x** binary still links against:
+
+- `libwasmvm.x86_64.so`
+- `libwasmvm152.x86_64.so`
+- `libwasmvm154.x86_64.so`
+- `libwasmvm155.x86_64.so`
+
+If `libwasmvm154.x86_64.so` is no longer available when the node is still running the **v6.3.x** binary, startup fails with an error like:
+
+```text
+error while loading shared libraries: libwasmvm154.x86_64.so: cannot open shared object file: No such file or directory
+```