docs: document inherit profile for non-Anthropic providers (#1036) (#1185)

Users on OpenRouter or local models get unexpected API costs because
GSD's default 'balanced' profile spawns specific Anthropic models for
subagents. The 'inherit' profile exists but wasn't well-documented for
this use case.

Changes:
- model-profiles.md: add 'Using Non-Anthropic Models' section explaining
  when and how to use inherit profile
- model-profiles.md: update inherit description to mention OpenRouter and
  local models
- settings.md: update Inherit option description to mention OpenRouter
  and local models (was only mentioning OpenCode)

Closes #1036

get-shit-done/references/model-profiles.md

@@ -40,8 +40,26 @@ Model profiles control which Claude model each GSD agent uses. This allows balan
 **inherit** - Follow the current session model
 - All agents resolve to `inherit`
 - Best when you switch models interactively (for example OpenCode `/model`)
+- **Required when using non-Anthropic providers** (OpenRouter, local models, etc.) — otherwise GSD may call Anthropic models directly, incurring unexpected costs
 - Use when: you want GSD to follow your currently selected runtime model
 
+## Using Non-Anthropic Models (OpenRouter, Local, etc.)
+
+If you're using Claude Code with OpenRouter, a local model, or any non-Anthropic provider, set the `inherit` profile to prevent GSD from calling Anthropic models for subagents:
+
+```bash
+# Via settings command
+/gsd:settings
+# → Select "Inherit" for model profile
+
+# Or manually in .planning/config.json
+{
+  "model_profile": "inherit"
+}
+```
+
+Without `inherit`, GSD's default `balanced` profile spawns specific Anthropic models (`opus`, `sonnet`, `haiku`) for each agent type, which can result in additional API costs through your non-Anthropic provider.
+
 ## Resolution Logic
 
 Orchestrators resolve model before spawning:

get-shit-done/workflows/settings.md

@@ -49,7 +49,7 @@ AskUserQuestion([
       { label: "Quality", description: "Opus everywhere except verification (highest cost)" },
       { label: "Balanced (Recommended)", description: "Opus for planning, Sonnet for research/execution/verification" },
       { label: "Budget", description: "Sonnet for writing, Haiku for research/verification (lowest cost)" },
-      { label: "Inherit", description: "Use current session model for all agents (best for OpenCode /model)" }
+      { label: "Inherit", description: "Use current session model for all agents (best for OpenRouter, local models, or runtime model switching)" }
     ]
   },
   {