feat: documentation pages and updated model pricing

- Add 13 documentation pages under /docs (getting-started, concepts, SDK refs, integrations, API reference, self-hosting, OpenCode plugin)
- Shared docs layout with collapsible sidebar navigation
- Update model pricing across all SDKs: add GPT-5.x, GPT-4.1, o3/o4-mini, Claude 4.5 series, claude-opus-4-6
- Update trace-analytics context window lookup with current models

packages/opencode-plugin/src/utils.ts

@@ -52,13 +52,32 @@ export function extractToolMetadata(
 }
 
 const MODEL_COSTS: Record<string, { input: number; output: number }> = {
-  "claude-opus-4-20250514": { input: 15, output: 75 },
-  "claude-sonnet-4-20250514": { input: 3, output: 15 },
-  "claude-haiku-3-20250307": { input: 0.25, output: 1.25 },
+  "gpt-5.2": { input: 1.75, output: 14 },
+  "gpt-5.1": { input: 1.25, output: 10 },
+  "gpt-5": { input: 1.25, output: 10 },
+  "gpt-5-mini": { input: 0.25, output: 2 },
+  "gpt-5-nano": { input: 0.05, output: 0.4 },
+  "gpt-4.1": { input: 2, output: 8 },
+  "gpt-4.1-mini": { input: 0.4, output: 1.6 },
+  "gpt-4.1-nano": { input: 0.1, output: 0.4 },
+  "o3": { input: 2, output: 8 },
+  "o3-mini": { input: 1.1, output: 4.4 },
+  "o4-mini": { input: 1.1, output: 4.4 },
+  "o1": { input: 15, output: 60 },
   "gpt-4o": { input: 2.5, output: 10 },
   "gpt-4o-mini": { input: 0.15, output: 0.6 },
   "gpt-4-turbo": { input: 10, output: 30 },
-  "o3-mini": { input: 1.1, output: 4.4 },
+  "gpt-4": { input: 30, output: 60 },
+  "claude-opus-4-6": { input: 5, output: 25 },
+  "claude-opus-4-20250514": { input: 15, output: 75 },
+  "claude-sonnet-4-20250514": { input: 3, output: 15 },
+  "claude-4.5-opus": { input: 5, output: 25 },
+  "claude-4.5-sonnet": { input: 3, output: 15 },
+  "claude-4.5-haiku": { input: 1, output: 5 },
+  "claude-3-5-sonnet": { input: 3, output: 15 },
+  "claude-3-5-haiku": { input: 0.8, output: 4 },
+  "claude-3-opus": { input: 15, output: 75 },
+  "claude-3-haiku": { input: 0.25, output: 1.25 },
 };
 
 export function getModelCost(