feat(hooks): add edit-error-recovery hook for handling Edit tool errors (opencode#4718)

- Detects Edit tool errors (oldString/newString mismatches)
- Injects system reminder forcing AI to read file, verify state, apologize
- Includes comprehensive test suite (8 tests)
- Integrates with hook system and configuration schema

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

src/hooks/edit-error-recovery/index.ts

@@ -0,0 +1,57 @@
+import type { PluginInput } from "@opencode-ai/plugin"
+
+/**
+ * Known Edit tool error patterns that indicate the AI made a mistake
+ */
+export const EDIT_ERROR_PATTERNS = [
+  "oldString and newString must be different",
+  "oldString not found",
+  "oldString found multiple times",
+] as const
+
+/**
+ * System reminder injected when Edit tool fails due to AI mistake
+ * Short, direct, and commanding - forces immediate corrective action
+ */
+export const EDIT_ERROR_REMINDER = `
+[EDIT ERROR - IMMEDIATE ACTION REQUIRED]
+
+You made an Edit mistake. STOP and do this NOW:
+
+1. READ the file immediately to see its ACTUAL current state
+2. VERIFY what the content really looks like (your assumption was wrong)
+3. APOLOGIZE briefly to the user for the error
+4. CONTINUE with corrected action based on the real file content
+
+DO NOT attempt another edit until you've read and verified the file state.
+`
+
+/**
+ * Detects Edit tool errors caused by AI mistakes and injects a recovery reminder
+ *
+ * This hook catches common Edit tool failures:
+ * - oldString and newString must be different (trying to "edit" to same content)
+ * - oldString not found (wrong assumption about file content)
+ * - oldString found multiple times (ambiguous match, need more context)
+ *
+ * @see https://github.com/sst/opencode/issues/4718
+ */
+export function createEditErrorRecoveryHook(_ctx: PluginInput) {
+  return {
+    "tool.execute.after": async (
+      input: { tool: string; sessionID: string; callID: string },
+      output: { title: string; output: string; metadata: unknown }
+    ) => {
+      if (input.tool.toLowerCase() !== "edit") return
+
+      const outputLower = output.output.toLowerCase()
+      const hasEditError = EDIT_ERROR_PATTERNS.some((pattern) =>
+        outputLower.includes(pattern.toLowerCase())
+      )
+
+      if (hasEditError) {
+        output.output += `\n${EDIT_ERROR_REMINDER}`
+      }
+    },
+  }
+}