feat(hooks): add tool-output-truncator for dynamic context-aware truncation

Refactor grep-output-truncator into a general-purpose tool-output-truncator
that applies dynamic truncation to multiple tools based on context window usage.

Truncated tools:
- Grep, safe_grep (existing)
- Glob, safe_glob (new)
- lsp_find_references (new)
- lsp_document_symbols (new)
- lsp_workspace_symbols (new)
- lsp_diagnostics (new)
- ast_grep_search (new)

Uses the new dynamic-truncator utility from shared/ for context-aware
output size limits based on remaining context window tokens.

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/hooks/tool-output-truncator.ts

@@ -0,0 +1,38 @@
+import type { PluginInput } from "@opencode-ai/plugin"
+import { createDynamicTruncator } from "../shared/dynamic-truncator"
+
+const TRUNCATABLE_TOOLS = [
+  "Grep",
+  "safe_grep",
+  "Glob",
+  "safe_glob",
+  "lsp_find_references",
+  "lsp_document_symbols",
+  "lsp_workspace_symbols",
+  "lsp_diagnostics",
+  "ast_grep_search",
+]
+
+export function createToolOutputTruncatorHook(ctx: PluginInput) {
+  const truncator = createDynamicTruncator(ctx)
+
+  const toolExecuteAfter = async (
+    input: { tool: string; sessionID: string; callID: string },
+    output: { title: string; output: string; metadata: unknown }
+  ) => {
+    if (!TRUNCATABLE_TOOLS.includes(input.tool)) return
+
+    try {
+      const { result, truncated } = await truncator.truncate(input.sessionID, output.output)
+      if (truncated) {
+        output.output = result
+      }
+    } catch {
+      // Graceful degradation - don't break tool execution
+    }
+  }
+
+  return {
+    "tool.execute.after": toolExecuteAfter,
+  }
+}