fix(failover): warn about warm on a remote target, align the spec

The spec promised a load-time warning when a chain marks a remote
target warm, where the flag does nothing; the loader now logs it. The
remote-backend test moves into ModelConfig.IsRemoteProxy so the loader
and the failover manager agree on what is remote.

The spec now says what ships: a load blocked by pinned warm targets
proceeds over the limit after eviction retries, without an error that
names them.

Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

docs/content/features/model-failover.md

@@ -107,6 +107,9 @@ count toward the active backend limit (`--max-active-backends`) like any
 pinned model: LocalAI never evicts them to make room, and if they fill the
 limit, a new model still loads rather than being blocked.
 
+`warm` applies only to local targets. On a remote (`cloud-proxy`) target it
+has no effect, and LocalAI logs a warning when it loads the chain.
+
 ## Realtime pipelines
 
 A pipeline stage can name a chain:

docs/superpowers/specs/2026-09-26-model-failover-chains-design.md

@@ -190,7 +190,9 @@ this.
 The manager loads `warm: true` targets at startup and marks them pinned in the
 watchdog, so LRU and idle eviction skip them. They still count toward the
 active backend limit. When pinned warm targets leave no room for another load,
-that load fails with an error that names them. The docs state this.
+the loader never evicts them: it retries eviction and then loads the model
+anyway, over the limit, with no error that names the warm targets. The docs
+state this.
 
 ### Events