fix: Ollama Cloud auth, /model switch persistence, and alias tab completion

- Add OLLAMA_API_KEY to credential resolution chain for ollama.com endpoints
- Update requested_provider/_explicit_api_key/_explicit_base_url after /model
  switch so _ensure_runtime_credentials() doesn't revert the switch
- Pass base_url/api_key from fallback config to resolve_provider_client()
- Add DirectAlias system: user-configurable model_aliases in config.yaml
  checked before catalog resolution, with reverse lookup by model ID
- Add /model tab completion showing aliases with provider metadata

Co-authored-by: LucidPaths <LucidPaths@users.noreply.github.com>

cli.py

@@ -3606,14 +3606,19 @@ class HermesCLI:
             _cprint(f"  ✗ {result.error_message}")
             return
 
-        # Apply to CLI state
+        # Apply to CLI state.
+        # Update requested_provider so _ensure_runtime_credentials() doesn't
+        # overwrite the switch on the next turn (it re-resolves from this).
         old_model = self.model
         self.model = result.new_model
         self.provider = result.target_provider
+        self.requested_provider = result.target_provider
         if result.api_key:
             self.api_key = result.api_key
+            self._explicit_api_key = result.api_key
         if result.base_url:
             self.base_url = result.base_url
+            self._explicit_base_url = result.base_url
         if result.api_mode:
             self.api_mode = result.api_mode
 
@@ -3630,6 +3635,15 @@ class HermesCLI:
             except Exception as exc:
                 _cprint(f"  ⚠ Agent swap failed ({exc}); change applied to next session.")
 
+        # Store a note to prepend to the next user message so the model
+        # knows a switch occurred (avoids injecting system messages mid-history
+        # which breaks providers and prompt caching).
+        self._pending_model_switch_note = (
+            f"[Note: model was just switched from {old_model} to {result.new_model} "
+            f"via {result.provider_label or result.target_provider}. "
+            f"Adjust your self-identification accordingly.]"
+        )
+
         # Display confirmation with full metadata
         provider_label = result.provider_label or result.target_provider
         _cprint(f"  ✓ Model switched: {result.new_model}")
@@ -6347,6 +6361,11 @@ class HermesCLI:
             def run_agent():
                 nonlocal result
                 agent_message = _voice_prefix + message if _voice_prefix else message
+                # Prepend pending model switch note so the model knows about the switch
+                _msn = getattr(self, '_pending_model_switch_note', None)
+                if _msn:
+                    agent_message = _msn + "\n\n" + agent_message
+                    self._pending_model_switch_note = None
                 try:
                     result = self.agent.run_conversation(
                         user_message=agent_message,