chore(kb/ai): review and expand

knowledge base/ai/opencode.md

@@ -23,23 +23,77 @@ docker run -it --rm 'ghcr.io/anomalyco/opencode'
 mise use -g 'opencode'
 nix run 'nixpkgs#opencode'
 npm i -g 'opencode-ai@latest'
+pacman -S 'opencode'
 paru -S 'opencode-bin'
 
 # Desktop app
 brew install --cask 'opencode-desktop'
 ```
 
+Configure OpenCode using `opencode.json` (or `.jsonc`) configuration files.<br/>
+Configuration files are merged, not replaced. Settings from more specific ones override those of the same name in less
+specific ones.
+
+| Scope   | Location                                        | Summary                   |
+| ------- | ----------------------------------------------- | ------------------------- |
+| Remote  | `.well-known/opencode`                          | organizational defaults   |
+| Global  | `~/.config/opencode/opencode.json`              | user preferences          |
+| Custom  | `OPENCODE_CONFIG` environment variable          | custom overrides          |
+| Project | `opencode.json` in the project's directory      | project-specific settings |
+| Agent   | `.opencode` directories                         | agents, commands, plugins |
+| Inline  | `OPENCODE_CONFIG_CONTENT` environment variables | runtime overrides         |
+
+```json
+{
+  "$schema": "https://opencode.ai/config.json",
+  "provider": {
+    "ollama": {
+      "npm": "@ai-sdk/openai-compatible",
+      "name": "Ollama (local)",
+      "options": {
+        "baseURL": "http://localhost:11434/v1"
+      },
+      "models": {
+        "llama2": {
+          "name": "Llama 2"
+        }
+      }
+    }
+  }
+}
+```
+
 </details>
 
-<!-- Uncomment if used
 <details>
   <summary>Usage</summary>
 
 ```sh
+# Start in interactive mode.
+opencode
+opencode 'path/to/directory'
+
+# List available models.
+opencode models
+opencode models 'anthropic'
+
+# Update the cashed models list.
+opencode models --refresh
+
+# Run tasks in headless mode.
+opencode run "Explain how closures work in JavaScript"
+
+# Start a headless server.
+opencode serve
+
+# Attach to headless servers.
+opencode run --attach 'http://localhost:4096' "Explain async/await in JavaScript"
+
+# List existing agents.
+opencode agent list
 ```
 
 </details>
--->
 
 <!-- Uncomment if used
 <details>