feat(providers): extend request_timeout_seconds to all client paths

Follow-up on top of mvanhorn's cherry-picked commit. Original PR only
wired request_timeout_seconds into the explicit-creds OpenAI branch at
run_agent.py init; router-based implicit auth, native Anthropic, and the
fallback chain were still hardcoded to SDK defaults.

- agent/anthropic_adapter.py: build_anthropic_client() accepts an optional
  timeout kwarg (default 900s preserved when unset/invalid).
- run_agent.py: resolve per-provider/per-model timeout once at init; apply
  to Anthropic native init + post-refresh rebuild + stale/interrupt
  rebuilds + switch_model + _restore_primary_runtime + the OpenAI
  implicit-auth path + _try_activate_fallback (with immediate client
  rebuild so the first fallback request carries the configured timeout).
- tests: cover anthropic adapter kwarg honoring; widen mock signatures
  to accept the new timeout kwarg.
- docs/example: clarify that the knob now applies to every transport,
  the fallback chain, and rebuilds after credential rotation.

run_agent.py

@@ -964,6 +964,12 @@ class AIAgent:
         self._anthropic_client = None
         self._is_anthropic_oauth = False
 
+        # Resolve per-provider / per-model request timeout once up front so
+        # every client construction path below (Anthropic native, OpenAI-wire,
+        # router-based implicit auth) can apply it consistently.  Bedrock
+        # Claude uses its own timeout path and is not covered here.
+        _provider_timeout = get_provider_request_timeout(self.provider, self.model)
+
         if self.api_mode == "anthropic_messages":
             from agent.anthropic_adapter import build_anthropic_client, resolve_anthropic_token
             # Bedrock + Claude → use AnthropicBedrock SDK for full feature parity
@@ -995,7 +1001,7 @@ class AIAgent:
                 self._anthropic_base_url = base_url
                 from agent.anthropic_adapter import _is_oauth_token as _is_oat
                 self._is_anthropic_oauth = _is_oat(effective_key)
-                self._anthropic_client = build_anthropic_client(effective_key, base_url)
+                self._anthropic_client = build_anthropic_client(effective_key, base_url, timeout=_provider_timeout)
                 # No OpenAI client needed for Anthropic mode
                 self.client = None
                 self._client_kwargs = {}
@@ -1035,7 +1041,6 @@ class AIAgent:
                 # Explicit credentials from CLI/gateway — construct directly.
                 # The runtime provider resolver already handled auth for us.
                 client_kwargs = {"api_key": api_key, "base_url": base_url}
-                _provider_timeout = get_provider_request_timeout(self.provider, self.model)
                 if _provider_timeout is not None:
                     client_kwargs["timeout"] = _provider_timeout
                 if self.provider == "copilot-acp":
@@ -1068,6 +1073,8 @@ class AIAgent:
                         "api_key": _routed_client.api_key,
                         "base_url": str(_routed_client.base_url),
                     }
+                    if _provider_timeout is not None:
+                        client_kwargs["timeout"] = _provider_timeout
                     # Preserve any default_headers the router set
                     if hasattr(_routed_client, '_default_headers') and _routed_client._default_headers:
                         client_kwargs["default_headers"] = dict(_routed_client._default_headers)
@@ -1796,6 +1803,7 @@ class AIAgent:
             self._anthropic_base_url = base_url or getattr(self, "_anthropic_base_url", None)
             self._anthropic_client = build_anthropic_client(
                 effective_key, self._anthropic_base_url,
+                timeout=get_provider_request_timeout(self.provider, self.model),
             )
             self._is_anthropic_oauth = _is_oauth_token(effective_key)
             self.client = None
@@ -1807,6 +1815,9 @@ class AIAgent:
                 "api_key": effective_key,
                 "base_url": effective_base,
             }
+            _sm_timeout = get_provider_request_timeout(self.provider, self.model)
+            if _sm_timeout is not None:
+                self._client_kwargs["timeout"] = _sm_timeout
             self.client = self._create_openai_client(
                 dict(self._client_kwargs),
                 reason="switch_model",
@@ -5233,7 +5244,11 @@ class AIAgent:
             pass
 
         try:
-            self._anthropic_client = build_anthropic_client(new_token, getattr(self, "_anthropic_base_url", None))
+            self._anthropic_client = build_anthropic_client(
+                new_token,
+                getattr(self, "_anthropic_base_url", None),
+                timeout=get_provider_request_timeout(self.provider, self.model),
+            )
         except Exception as exc:
             logger.warning("Failed to rebuild Anthropic client after credential refresh: %s", exc)
             return False
@@ -5275,7 +5290,10 @@ class AIAgent:
 
             self._anthropic_api_key = runtime_key
             self._anthropic_base_url = runtime_base
-            self._anthropic_client = build_anthropic_client(runtime_key, runtime_base)
+            self._anthropic_client = build_anthropic_client(
+                runtime_key, runtime_base,
+                timeout=get_provider_request_timeout(self.provider, self.model),
+            )
             self._is_anthropic_oauth = _is_oauth_token(runtime_key)
             self.api_key = runtime_key
             self.base_url = runtime_base
@@ -5487,6 +5505,7 @@ class AIAgent:
                         self._anthropic_client = build_anthropic_client(
                             self._anthropic_api_key,
                             getattr(self, "_anthropic_base_url", None),
+                            timeout=get_provider_request_timeout(self.provider, self.model),
                         )
                     else:
                         rc = request_client_holder.get("client")
@@ -5518,6 +5537,7 @@ class AIAgent:
                         self._anthropic_client = build_anthropic_client(
                             self._anthropic_api_key,
                             getattr(self, "_anthropic_base_url", None),
+                            timeout=get_provider_request_timeout(self.provider, self.model),
                         )
                     else:
                         request_client = request_client_holder.get("client")
@@ -6246,6 +6266,7 @@ class AIAgent:
                         self._anthropic_client = build_anthropic_client(
                             self._anthropic_api_key,
                             getattr(self, "_anthropic_base_url", None),
+                            timeout=get_provider_request_timeout(self.provider, self.model),
                         )
                     else:
                         request_client = request_client_holder.get("client")
@@ -6402,6 +6423,11 @@ class AIAgent:
             self.api_mode = fb_api_mode
             self._fallback_activated = True
 
+            # Honor per-provider / per-model request_timeout_seconds for the
+            # fallback target (same knob the primary client uses).  None = use
+            # SDK default.
+            _fb_timeout = get_provider_request_timeout(fb_provider, fb_model)
+
             if fb_api_mode == "anthropic_messages":
                 # Build native Anthropic client instead of using OpenAI client
                 from agent.anthropic_adapter import build_anthropic_client, resolve_anthropic_token, _is_oauth_token
@@ -6409,7 +6435,9 @@ class AIAgent:
                 self.api_key = effective_key
                 self._anthropic_api_key = effective_key
                 self._anthropic_base_url = fb_base_url
-                self._anthropic_client = build_anthropic_client(effective_key, self._anthropic_base_url)
+                self._anthropic_client = build_anthropic_client(
+                    effective_key, self._anthropic_base_url, timeout=_fb_timeout,
+                )
                 self._is_anthropic_oauth = _is_oauth_token(effective_key)
                 self.client = None
                 self._client_kwargs = {}
@@ -6433,6 +6461,12 @@ class AIAgent:
                     "base_url": fb_base_url,
                     **({"default_headers": dict(fb_headers)} if fb_headers else {}),
                 }
+                if _fb_timeout is not None:
+                    self._client_kwargs["timeout"] = _fb_timeout
+                    # Rebuild the shared OpenAI client so the configured
+                    # timeout takes effect on the very next fallback request,
+                    # not only after a later credential-rotation rebuild.
+                    self._replace_primary_openai_client(reason="fallback_timeout_apply")
 
             # Re-evaluate prompt caching for the new provider/model
             is_native_anthropic = fb_api_mode == "anthropic_messages" and fb_provider == "anthropic"
@@ -6506,6 +6540,7 @@ class AIAgent:
                 self._anthropic_base_url = rt["anthropic_base_url"]
                 self._anthropic_client = build_anthropic_client(
                     rt["anthropic_api_key"], rt["anthropic_base_url"],
+                    timeout=get_provider_request_timeout(self.provider, self.model),
                 )
                 self._is_anthropic_oauth = rt["is_anthropic_oauth"]
                 self.client = None
@@ -6602,6 +6637,7 @@ class AIAgent:
                 self._anthropic_base_url = rt["anthropic_base_url"]
                 self._anthropic_client = build_anthropic_client(
                     rt["anthropic_api_key"], rt["anthropic_base_url"],
+                    timeout=get_provider_request_timeout(self.provider, self.model),
                 )
                 self._is_anthropic_oauth = rt["is_anthropic_oauth"]
                 self.client = None