fix(ollama): unify context window handling across discovery, merge, and OpenAI-compat transport (#29205)

* fix(ollama): inject num_ctx for OpenAI-compatible transport

* fix(ollama): discover per-model context and preserve higher limits

* fix(agents): prefer matching provider model for fallback limits

* fix(types): require numeric token limits in provider model merge

* fix(types): accept unknown payload in ollama num_ctx wrapper

* fix(types): simplify ollama settled-result extraction

* config(models): add provider flag for Ollama OpenAI num_ctx injection

* config(schema): allow provider num_ctx injection flag

* config(labels): label provider num_ctx injection flag

* config(help): document provider num_ctx injection flag

* agents(ollama): gate OpenAI num_ctx injection with provider config

* tests(ollama): cover provider num_ctx injection flag behavior

* docs(config): list provider num_ctx injection option

* docs(ollama): document OpenAI num_ctx injection toggle

* docs(config): clarify merge token-limit precedence

* config(help): note merge uses higher model token limits

* fix(ollama): cap /api/show discovery concurrency

* fix(ollama): restrict num_ctx injection to OpenAI compat

* tests(ollama): cover ipv6 and compat num_ctx gating

* fix(ollama): detect remote compat endpoints for ollama-labeled providers

* fix(ollama): cap per-model /api/show lookups to bound discovery load

docs/providers/ollama.md

@@ -199,6 +199,7 @@ If you need to use the OpenAI-compatible endpoint instead (e.g., behind a proxy
       ollama: {
         baseUrl: "http://ollama-host:11434/v1",
         api: "openai-completions",
+        injectNumCtxForOpenAICompat: true, // default: true
         apiKey: "ollama-local",
         models: [...]
       }
@@ -209,6 +210,24 @@ If you need to use the OpenAI-compatible endpoint instead (e.g., behind a proxy
 
 This mode may not support streaming + tool calling simultaneously. You may need to disable streaming with `params: { streaming: false }` in model config.
 
+When `api: "openai-completions"` is used with Ollama, OpenClaw injects `options.num_ctx` by default so Ollama does not silently fall back to a 4096 context window. If your proxy/upstream rejects unknown `options` fields, disable this behavior:
+
+```json5
+{
+  models: {
+    providers: {
+      ollama: {
+        baseUrl: "http://ollama-host:11434/v1",
+        api: "openai-completions",
+        injectNumCtxForOpenAICompat: false,
+        apiKey: "ollama-local",
+        models: [...]
+      }
+    }
+  }
+}
+```
+
 ### Context windows
 
 For auto-discovered models, OpenClaw uses the context window reported by Ollama when available, otherwise it defaults to `8192`. You can override `contextWindow` and `maxTokens` in explicit provider config.